If you decide on the agms, a smaller portable panel (25 watts) may be sufficient. maybe nothing beyond your existing panels.
We park ours, in the winter months on the south side of our home, where it is shaded by two homes, 24 plus high, 20 feet apart,, and a row of tall Washingtonia palms planted in our neighbors side yard by the previous owner.
Not a carport, but very shady.
I check our agms every few weeks. Unless we leave something turned on, we don't have to plug in.
But, we're in Florida.
Sherry