How do you remake with 5 votes and 0 against?

The remake will still be valid if the vote was triggered and they come back, their vote doesn't actually matter.

I did this a couple days ago the person came back just as we started the vote and by that time they're at least a level down and I think many people would still agree to remake.

The person has to be afk for a certain amount of time before the vote triggers. The person could be gone the entire time, be there at the start and then d/c, connect late, or even drop in and out. As long as the player is missing for the required total period of time, the vote can trigger.