OP here - Nope, no heat pump or heat strips. And the roof AC compressor isn't really practical in the winter in Minnesota.
Here's what I did: I did run a space heater on high for 1 hr. It's 1500 watts I think and the generator is 4000 watts. So I'm only at about 38% load. I guess I need another space heater to get the load closer to 50%.
I have always used Seafoam over the winter with a full gas tank.
The reason I'm asking all this is I ran into an issue where the generator didn't start. I had missed running it a couple months over the summer. The Cummins shop got it working again but I'd rather not drop $300 again.