My top tip is to head small and local. Lift passes so much cheaper, somewhere to stay is much cheaper, supermarkets much cheaper etc etc. They are generally lower though which can be risky if booking ahead and no idea snow wise.
Alternantively….I once headed to Val d’Isere to see friends who were stying there. I couldn’t find anyhwere for less than 100 euros per night for just me at short notice. I found a youth hostel 25km down the road which for 25 euros per person per night gave you breakfast, evening meal, dormitory style accomodation, evening meal and free shuttle bus to Val d’Isere or Tignes! Might be able to book family rooms.
Hmmm < looks out of home office window.> “Oh look, there’s the alps, ” <turns head>. “Oh look there’s Grenoble Airport” 😀
I used to go for some real cheap ski holidays when I lived in London. We’d drive through a day and night without stopping to get to the alps, stay in one of those French resorts designed for families where it’s just self catering appartment blocks rather than chalets & hotels. Didn’t have that chocolate box prettiness, but the skiing was just as good… and damn cheap!