Please help with solar and electrical questions...

Remember, solar doesn't do well when under shade trees. Unless your off grid locations will have a lot of sun exposure, you may come up short.
You can do a lot better than $800 for 190 watts and the controller.
I'd suggest an after market approach on the solar, 200-300 watts and use the extra money for a small generator for the time that clouds and rain stall your charging.