I can't comment on resorts that allow dogs but can certainly give you some heads up on motorhome areas as done a few when saving money doing the racing graft with the lad.
Pila (Italy) - Carpark at bottom of main lift station. Keep to side on the shops side as they are cool with that and you can walk (in boots) to main lifts. Also walking distance for eating out from carpark and supermarket is opposite car park.
La Tania (Meribel) - Carpark on left in La Tania which is a drop down from the road on left hand side. They do charge but like a bird its cheeep!
Meiringen (Switzerland) - In the town of Meiringen at the top part there is a main carpark for the lift which is just by the river. If you park way down at the bottom so immediately as you enter the car park then they are cool with that. It is a trek though to the lift and over to the main town stretch - would say around 20mins walk to coop supermarket in town and around 10mins to lift from where you will be parked. Dont try parking up on the mountain as they do not like this at all.
Champery Les Crosets (Switzerland) - Massive carpark and you pay in the lift office for your motorhome ticket. Need long extension lead as this draps off the back of the carpark to the underground carpark below so make sure you have one for elec hook up. Walking distance to lifts but get stocked up on food before you get there as know super markets within easy walking distance.
Flaine (France) - Plenty of different areas here - some with elec hook up and some without. We stayed at the 'Stages' area which is where my lad was race training. This is the bottom car park quite a stint from the main Flaine shoppy type of area. Lots of motorhomes were next to us. But I would say you are better staying in the Flaine shopping part (also where main lift ticket office is...) where there is a dedicated motorhome area with elec and short walk from town area.
Anyway theres a few to get you started - will add more later..