It's possible, but casters will have a field day

Lost Mines of Phandelver has a lot, muito of encounters that consist of mostly low HP enemies that will die to a single AoE spell, two tops. At first this might not seem like a big deal, but it is when you combine a lot of easily AoE'd squishy enemies with the ability to get your spell slots back very, very quickly.

LMoP ends before your players will get access to true powerhouse spells like Fireball which will instantly end encounters, but a lot of first level spells will easily end encounters if you can simply spam them.

Even with only a single spellslot, a warlock who can get their spells back in 5 minutes will have no reason not to blow up everything in sight, then rest 5 minutes and do it again in the next fight. This will make your non-spellcasters feel a lot less exciting, because those classes are generally better in longer drawn out days where you can't simply unload all your resources into a single problem.

Now this might not be a problem if your casters mostly use spells like Sleep, but if you have a caster who specializes in blowing things to kingdom come you'll see a lot of fights end before your rogue and fighter have even gotten to the fight, leading to frustration.

The only fight I can come up with where your players are likely not going to notice the difference is the dragon, in the rest of the fights, classes specialized in spending x-per-rest resources will feel far stronger than your rogues or fighters. Considering you have first-time players, this might make some people think this is how D&D is always going to be, and they'll be turned off from playing characters that work better in drawn-out days because they believe they are vastly inferior to casters with AoE spells. (A problem I've encountered DMing for new players even when not using epic heroism.)

Shorter rests really won't help with the initial fights, because they're spaced closely together in tempo. If you alter the goblins in the cave, you don't have 5 minutes for a short rest, much less an hour for a long rest.

The solution is a small supply of extra HP at 1st level.

The simplest/cleanest thing you can do to make the initial encounters of Lost Mines of Phandelver more survivable, while having reduced impact as the characters level up, is to give them some bonus HP at 1st level.

At 1st level, and second level, those extra HP are a significant increase to survivability, virtually eliminating the one-hit kill concern. At 5th level, it's not a huge difference. By the time you hit 10th level, you're not going to need or notice it.

I've run LMoP twice.

A primeira vez, the goblin cave was effectively a complete party wipe, with the wizard (at 1 HP) dragging his unconscious/dead companions away from the cave as fast as he could. (It didn't help that the party alerted the goblins to their presence and the rogue, attempting to scout the bushes outside the cave got tagged by dois natural 20s.)

A segunda vez, I gave everyone half their CON in bonus HP at first level, rather than their CON modifier. (It amounts to 5 extra HP.) Those initial fights were still tough, and dangerous, due to the lack of available healing, but it didn't come close to a TPK.

Use of Rest Variation.

As the DM it is entirely appropriate for you to select if you use variant rules, such as Epic Heroism. There are a few things to think about though. Spell-casters can end up having a bit of an advantage over other classes with Epic Heroism. You may also want to consider whether you "change back" once the characters have levelled-up and are more powerful/capabable. You could also end up making more work for yourself if you continue to apply Epic Heroism and then need to keep adjusting encounters; unless you're writing your own adventures to take this into account. A different option that you may consider is to let the characters use the Healing Surge variant rule (DMG p266) until they gain some levels/experience.

Another few things to consider:

• Como Mestre, você pode dar aos oponentes uma "desvantagem" por seus ataques e danos, ou escalar o número de oponentes, para facilitar um pouco as coisas até que os personagens fiquem um pouco mais habilidosos ou outros participem do grupo. (Essa é essencialmente uma variante / mix de Ignorando os dados (DMG p236) e o DM que determina as consequências (Resolução e conseqüências, DMG p242).

• Você pode enviar um NPC (ou alguns) junto com o grupo para ajudar, mas lembre-se de não "assumir" a peça. Os NPCs podem ser bons "atores de apoio" acompanhando ou saindo conforme necessário. Você pode manter os níveis dos NPCs "equilibrados" para os personagens, conforme necessário; se não faziam parte da última aventura, estavam apenas ganhando experiência em outro lugar. Eu usei essa técnica comigo mesmo, como Mestre, controlando o NPC com alguns jogadores novos com bons resultados, e você pode manter as coisas seguindo em frente se o grupo ficar parado. Há informações sobre opções para fazer isso em Membros do Partido NPC (DMG p92)

• Dependendo da experiência dos jogadores, você pode permitir que eles controlem mais de um personagem. Isso pode ser complicado, principalmente com jogadores mais novos, e pares de personagens (do mesmo jogador) às vezes podem se dar bem "muito bem". Usamos essa técnica muito jogando com pequenos grupos e é bom desde que os jogadores tratem os personagens como entidades separadas, não como uma entidade única com "dois corpos". Há alguns conselhos sobre isso em Pequenos grupos no DMG p236

À medida que outros jogadores entram no jogo, eles podem criar personagens do mesmo nível dos que já estão jogando, ou você pode permitir que eles assumam um NPC de longo prazo. A primeira opção provavelmente é melhor, pois eles têm uma melhor propriedade do personagem, e você pode manter o NPC para uso posterior, conforme necessário. Há conselhos sobre novos jogadores que se juntam à equipe no DMG p236 - Also remember that early on characters do level-up fairly quickly, and they'll be able to handle threats better.

Hope that's some help.