Yes, I have done this, using a cigarette lighter-type plug and receptacle available from Amazon, with the receptacle hard mounted on the camper. I have 2×185 watt panels that came with my NL 10-2, but sometimes I park it in a shed with no electricity and the panels on the roof don’t get any light. So, I bought a 50 watt panel and use it as a trickle charger. The solar panel is connected to my solar panel controller in the camper. Works good. Same concept could be used for more or bigger remote panels.
Yes. My 2014 8-11 did not come with factory solar and I added solar panels to roof and alternator DC charging using a Renogy combined controller into a lithium battery install.
Then I decided I wanted to add remote solar. I routed 10 gauge line with an Anderson connector down through the round vent at the bottom of the refrigeration compartment. Then through the interior wall into the area under the closet floor. There I installed a separate MPPT controller for the remote panel(s) with a breaker onto the battery area. No new exterior holes.
If your remote panels have their own controller then the install is easier.