Don't buy another panel later, buy it now... They may not have these 21x47" panels much longer. That is not a common size.
I have 200 watts of solar and 1 100ah AGM Lifeline battery.
We have led lights, a wave 3 heater, LED tv.... We use 15-20 ah a day.
We only use the furnace for quick warm up, It gobbles battery amps.
We watch tv about 2 hrs a night, read for an hr or more, charge our laptops/cell phones etc.
Unless we are in a dense forest or dead of winter and heavy cloud cover we easily recover our used AH by noon or better.
We do have our honda 2000 if needed.
We do not charge from the truck although I can... Just throw a switch.
Jim