If the company is reorganinzing itself under a Chapter 11 bankruptcy, then the US trustee is going to expect it to recover whatever monies it can. That's the bad news.
Now, for the good news. We don't have debtor's prisons in this country. The company could sue you for the return of the money. If it got a judgment, it could seek to collect it and that could include a wage garnishment in CA. However, a company that is undergoing a Chapter 11 BK reorganization sometimes needs the permission of the US trustee to incur legal expenses chasing after people. If you look like a "difficult" collection, the US trustee may tell the company to forget about it.
It probably depends upon how much is at stake here. For 5k, the amount might be too low to justify the legal costs. 25k is a different matter entirely.
Unfortunately, your company's current financial difficulties do not necessary provide you with "an out" with respect to the relocation expenses that you accepted in exchange for your agreement to work for them for one year. You would have a case for not paying them back if your current employer laid you off before the one year was up because you were able and willing to work and fulfill the terms of the agreement except for their decision to terminate your employment. But, it is you, not them, that is wanting out early.