Obtaining and installing larger Onan generator.

Hmmm. I can't see why you would need a bigger genny even with an electric range. A residential fridge uses less power than an absorption unit. The 7.5 should cover your needs. I second the suggestion for 500 to 800 watts of solar on the roof. You can also add 4 more batterys to the rear compartment. They fit perfectly. Good luck and happy trails.