I would rather pay an extra £100 or so to ski on pistes that have plenty of snow than save a few quid and worry for 2 months if there will even be enough snow!
As there is just 2 of you, i personally would wait and see where the snow is good and book a couple of weeks before, even if it will cost more money. most people only go once a year, why take the risk...nothing worse than skiing on patchy/muddy pistes!
Good luck ! not an easy choice