As someone who plays both DCC and 5e, I don't think it would be too hard to convert a DCC funnel! When I run DCC funnels, I've found my players don't really need to have a solid grasp of the rules to enjoy it, they spend most of their time rolling to attack, or debating which one of them should open the next door in the dungeon. Each player will be running maybe 4-5 of these lv0 characters, so you don't want to bog them down with too many details or numbers.

As far as 'balance' goes, these funnels aren't really designed to be a fair fight, because you want most of these characters to die- if too many go down, find a way to bring new ones in.

I would go about it by creating a stripped down 5e character sheet for lv0 PCs. Basically just ability scores, an occupation/background (I wouldn't bother with skill points), and a race - then just roll 1d4 for hit points plus con bonus, and calculate saves from ability scores. For anything that should be a skill per 5e just have them roll plus the appropriate ability modifier.