If you had not recently updated your fridge, I would say an upgrade would make sense with the power you are capturing and the efficiency you could gain. With your fridge update, you have a reliable unit that really does not need to be replaced but could be supplemented with a DC heater element. I do know I only capture about the half as much in the winter with the short days and overcast skies than the long summer days, so I am not sure how much reserve you will have if you camp year round verses seasonally or if you cannot chase the good weather and camp through the bad.
I have used AGM batteries that don't hold as much charge and typically just barely get to full charge in the summer when camping. In the winter, I still may supplement charge if am boon docking more than a couple days. What is nice is that every time we head out (about twice a month), the batteries are fully charged even though the camper is not plugged in.
Another thought is to add a hot rod to your water heater so you can heat water via AC instead of LPG. Maybe being able to switch the fridge and hot water heater between electric and LPG based on season and available sun would be a good option?
