Change gas out at least 1x a year. Can treat fuel as well to help out w/ issues you mentioned.

Use ethanol free fuel in small engines. Most issues arise from ethanol fuel. A lot of problems can be prevented by using ethanol free fuel.

We’ve run our home comfortably for 5-6 hours & used less than half of a tank of gas on the above linked Honda generator.

You could get a lot of run time out of 10 gallons of fuel + tank on generator.

Again—all situations different—ours is using natural gas fireplace to keep house warm (electricity needed for blower on fireplace).