I ran my solar wires down the fridge chimney. No holes, just double sided tape to hold the wires down, and VHB tape holding down the solar brackets.
With two panels you can run them in series. This doubles the voltage, but the charge controller can convert it back to what the batteries need. Going from 18 volts (used for 12v systems typically) to 37 volts (doubled) means you can use smaller wire, and just one pair of wires. The MPPT controller will bounce this down to the 14 volts needed.
There are lots and lots and lots of forum post about installing solar, so i wont go into any details further.