frozen sewer hose and water line

I would pour a bucket of really hot water into sinks hopefully that will at least thaw them to drain tanks

Water line? Internal to the RV or the hose connection to the spigot?
Hose is easy, bring it inside at night. Internal to the RV will depend on the RV and where the pipes are. Basically you need to apply heat by opening access areas inside or add heat to any basement compartment where to freeze up could be etc.

Sewer hose may need to wait for the sun to hit it tomorrow. I would close your drain valve if you can. Or it is the valve that is frozen? If you have waste pipes frozen you may need to get a space heater blowing on it tomorrow. Possibly boil some water and pour it over the sewer hose during the warmest part of the day.

Turn your heat on and hold hoses up near the exhaust to thaw them out. Had to do that last year. Works like a charm.

When will it be above freezing where you are? Wrapping the sewer hose in heat tape & foam insulation may help. Once you have water flow in the sewer line again, take a HOT shower in the trailer and let the water drain, the extra heat should help melt more of the ice in the line.