I can't remember the source but there is a terminal block made for fridge vent installations. It attaches to the vent base and wires are connected at that block. If pulling wires directly from roof top to controller, a grommet is the easiest and there are a variety of them made.
Home Depot sells these
Box entry fittings that are weather-proof. I used one on my roof top combiner box. It accepts two MC4 wires. I put some caulk on the entrance just to make sure everything is water tight. If you're able to make a hole in the fridge vent base, this fitting will be all you need and it is metal so won't be breaking or deteriorating from heat or UV.
