I can run both, not sure if I kept them on low, and turn off the water heater, hope your refrig is already cool, dont cook, keep your hair wet, etc. Turn one on first, let it run for a few minutes, then turn on the second. I think I was drawing about 12 amps on each side within the coach so less than 25 to the source.
Get an Electrical Management System, and it will tell you how much you are using on each side of you coach circuitry (along with the protection it provides as its primary application). This one is popular, there is another option that may be slightly less money.
Progressive Industries RV Surge and Electrical Protection industry lea