Startups are a lot harder for people with debt/no savings/kids/mortgages/etc, but there are plenty of cases where resourceful people found a way to make it work.
When you have debt and a huge-but-not-immediately lucrative opportunity in front of you, I imagine you'll manage like entrepreneurs have for centuries. Sleep on couches, eat ramen, rack up some more debt (credit cards?), dodge or persuade your creditors, etc... And hope that it works out.
I would advise to exhaust every possible better source of debt before turning to credit cards. Compound interest on your average credit card rate is brutal, and entrepreneurs going through high uncertainty shouldn't fall for the time-bomb promotional offers.
When you have debt and a huge-but-not-immediately lucrative opportunity in front of you, I imagine you'll manage like entrepreneurs have for centuries. Sleep on couches, eat ramen, rack up some more debt (credit cards?), dodge or persuade your creditors, etc... And hope that it works out.