Done is done, time to roll. I assume you were headed to a warmer place already so make some headway tomorrow.
Frozen tank is not usually an issue. Turn the pump off just in case you have a leak when it thaws out. You might be eating out for a bit and using the camp facility when possible. Limited use of the black tank at night should be fine.
Are you coming down Coast Highway? Should thaw out along the coast. Coos Bay is above freezing for at least a week. Can't speak for where to camp or where to have the plumbing checked out.
Good luck.