You should be OK although the WFCO is anemic at best for quickly recharging depleted batteries. You could opt for a portable charger with better charging characteristics or call Randy at bestconverters.com for an easy upgrade to your existing converter. All this can be figured out with some driveway camping and a voltmeter, you could simulate the conditions you expect at Yellowstone. We have a similar set-up and often RV in frigid temps running the genny less than a couple of hours daily to get batteries back to where they can provide another day of service. Adding at least 100 watts (100 watts per battery is better) of solar will greatly reduce genny use for simply charging batteries. Have a great time at Yellowstone!!!
