You will never have to worry about frozen lead-acid batteries down there.
Plenty 'o sunshine, and a solar panel line can be sneaked up and mounted through any breach in the trees.
Nobody will ever see it.
12V is 12V.
LEDs require almost no juice(amps). V=IR.
Ohms Law Calculator
Buy one solar panel from a cheap source (harbor fright) with a battery and play around with it.
You'll need an intelligent charging limiter with a gauge.
That might already be built in.
It either works, or it dont, for now.