If you can't use the place to become a landlord, can you rent a small efficiency apartment within biking distance of work for less than your current living situation (and the other associated expenses)?
You could live in the apartment Monday-Friday (and maybe one extra night mid-week) and then head home to the In-law's place for the weekends.
It's more time away from the family but depending on your financial situation, it might be worth exploring. If you are in emergency mode and a studio (or cheap hotel, even) costs you few hundred less than your current housing costs, it might be worth the move to the IL's place, with a crash pad to cut down the commute, for a while at least.