When does perseverence cross the line into stupidity?

I know exactly what I want to do for a living. I know the lab I want to work in and the experiments I want to do in it. I have been working there for free on the weekends for the last 10 weeks because I have a project that I love and really want to finish.

We found out this week that the lab absolutely, positively, for sure has no money until the fall at the earliest, and that is the best case scenario.

So do I keep working for free and get another job to support myself and wait for things to work themselves out, or jump ship?