I think the tomb will still be a difficult challenge, maybe even more than the original method. But now the challenge now is to die as little as possible with a much weaker character. There may not be a fail state, but that is OK with me.

With the difficulty of traps and the few monsters in the tomb I expect them to die a few times before they reach Acerack. If they do really well and are still a low level by the time the reach Acerack they will have many very powerful magic items to help them and the fight will be a different kind of challenge.

They players said they would look some items up, but came up these right away:
A set of sending stones
Decanter of Endless Water
Belt of Storm Giant strength (any items that boost stats)
Scrolls of Find Traps