A few things :
* you don't need a fridge in winter so you can just turn it off. * charging battery banks / laptops in sunny periods results in the battery bank being useful in times when the weather isn't so kind. * no amount of solar is enough in the deep of winter. * any amount of solar is too much in the height of summer. * pubs are great for charging devices. * lead acid batteries last substantially longer if you only let them drop to half their true capacity and regularly charge them. Yes alternatives exist but there's something to be said for making what you have work for as long as possible.
It is way too much power cause the thing is constantly being charged every time the sun shines and it is pretty hard to use 300ah in a campervan while you're sleeping.
The benefit of LiFePO4 over those AGM batteries, is that you can go to zero. It is worth every $ for that and for the weight savings (in a campervan).
Highly suggest checking out Will Prowse on YT. He's a great resource.