Those inverter generators don't last long.
And the ethanol in the gas makes them a pita to maintain.
The carbs get gummed up.
Also storing gas is a problem.
Suggest you get a dual fuel one and run off of propane.
Also its probably best not to load more than ~66 percent.
I may agree with the limited life of generators, inverter or not, but I may disagree with why.
IMHO the most wearing portion of such units, particular for the invertor generators, which if taken care of will run a very long time, is gasoline--which of course was mentioned.
I strongly recommend that you run a propane or natural gas unit. If you need guidance on how to convert an existing one please respond back (I am NOT in this business----I've just done it--my advice is gratis.)
Gasoline stores poorly (6 months), you can't get it after the power's gone out and the gas station, also out of power, can't pump it, and it, as mentioned, can gum up carburetors.
Still more, depending on the size of your propane tank(s) you may not need to have your wife refill the generator as frequently, with otherwise smelly and dirty gasoline on a hot engine.
May your ALS have as little effect on the quality of your life for as long as possible: prayers.