PVWatts will help you figure this out: https://pvwatts.nrel.gov

According to PVWatts, a 10kW solar system would get me very close to my average usage in December. I'd be way over in the summer, could probably get away with a 4kW system and dial back use during an outage. I can lease two Powerwall 3 batteries from my utility company for $55/mo.

Or look at: https://www.franklinwh.com/products/apower2-home-battery-bac...

Edit: this also looks like a good option: https://www.santansolar.com/product/the-homesteady-kit/

We used to lose power 3-4 days a winter in our old house. It would have been really nice to have heat. A generator or smaller system could handle that.

keep in mind the limitations of these forecasting calculations. On an AVERAGE day, assuming AVERAGE weather, assuming AVERAGE load, you should be fine.

The trouble with relying on the weather for your electricity is that it is entirely possible that you will go five days straight with cloud cover, limited to no solar generation and then be freezing. This is the problem that the electricity grid solves with varied sources of generation.