Originally Posted by accumack
Not using the humidifier really reduces the amount of power needed.
When I tent camped, I found that with the humidifier, I could get about a night and a half of sleep out of a regular truck battery. Without the humidifier, I could get a whole second night with minimal driving of the vehicle after the first night.
In my camper, I just used a cheap 100w power inverter in the camper's only 12v plug in the kitchen and an extension cord to the bedroom. I happily slept for a night that way, towed the whole day the next day, and slept happily the next night.
If I did it more often, I would install a 12v plug in directly in the bedroom. Or better, an inverter-powered outlet above my existing one.
For one night, you don't need anything special. If you do it regularly, then it is something to consider.