Yes both are supplied by the chassis battery via the battery control center (BCC). It's mounted on the firewall above and to the left of the engine air cleaner.
Rewiring is certainly possible by abandoning the original circuit and finding a free switched circuit. Probably the easiest way to power down would be to just enable the chassis battery disconnect. Just beware that the door steps are also powered by the chassis battery so the step out of the coach might be a bigger drop then expected if the disconnect is set.
2006 Hurricane 31D built on a 2006 Ford F53