never heard of the spreadsheet, although I imagine it exists.
let your budget and roof space dictate how much solar you get, it's hard to have too much, especially on an RV.
on sunny days, having too much means your recharged earlier... if you're partly shaded or it's cloudy, having too much means you get a bit of charging versus nothing
for sizing a battery bank, add up the amps for the gear you want to run, and multiply by the number of hours you want to run it. for AC loads on an inverter, take the ac amps and multiply by 10 to get a rough dc amperage.
