I would skip the generator and get 200 to 400 watts solar.
I doubt you will need air April/May but if you do get some hookups.
Was rather warm last month at Glacier. We were seeing 90+ and plugged in. Locals were saying it was the most heat ever. But you will be there early.
If you get a generator you also need to get a new converter such as the PD9260-14.8
WFCO is a trickle charge at 13.6 volts unless you are one of the lucky few where it actually works in boost mode.
http://www.bestconverter.com/PD-9260C-148-60-Amp-RV-Converter