I am an electrician who has installed a lot of generator hookups for home. You don't need to run everything,just the basics.Usually furnace, refridgerator, water pump if you have one, micro wave ,one receptical circuit and one lighting circuit would be minimum. This will be enough to let you get by comfortably.Generally speaking, you want one in the range of 5,000 watts for your house. For your RV you could get by with 2,000 watts to charge the batteries,run the microwave etc. If yoy want to run the A/C then you would need 3,000 watts.