Option 1: Full cook your chili in the Instant Pot or Slow Cooker. Let the chili cool in the fridge for 4 hours then transfer to a freezer container or bag and store for up to 3 months. Make sure to leave enough room for the liquid to expand by 30-40%. Defrost under refrigeration and then reheat in the microwave.
Option 2: Fully cook the ground meat. Then add the ground meat, onion, beans, pepper, squash, diced tomatoes, chili powder, salt, and chicken broth in a freezer friendly bag. Before cooking, add two cans of tomato sauce. Cook from frozen in the IP by pressuring cooking 10 minutes and letting it naturally release. Cook from frozen in the slow cooker by cooking on high for 6-8 hours. (I have not tested this method.)
Notes
To make it spicier, you can do one of two things:
Add 1 chopped jalapeno to cooking. Add it at the same time you add the beans and green pepper.
If you need to keep it mild for others but want a spicy version for yourself here is what I did: I added sprinkles of cayenne pepper the first night I ate it. But, when I went to store it I split the leftovers into TWO containers. In my container, I placed jalapeno slices on top. The next day when I went to eat it I removed the jalapeno slices but the chili was PLENTY spicy and delicious!