I know, I’ve been to them all. However, Les Portes du Soleil is the biggest ski area in Europe, and generally, people fly to Geneva to get there. The transfer from Geneva airport to Les Gets is actually about the same time wise as Moûtiers to Val Thorens (in my experience).
My point is that there’s around 8-9,000 people who fly from London to Geneva airport each winter Saturday, and vice versa. And at popular times, eg half term, the fares are astronomical. We are 6 months out, and the cheapest easyJet fare from London to Geneva on the morning of the first Saturday of February half term is £350 (one way) assuming you want to take a big bag. If you want the 0810 off Gatwick (arriving Geneva around 1100) it’s nearly twice that. The average across all airlines is nearly £500.
For many of the people flying to Geneva it would be quicker to get to St Pancras than to Gatwick / Stansted / Luton / Heathrow / City / Southend, and with a much shorter check in and a quicker exit the other end, then even with the same transfer the door to door time will be roughly similar. And clearly Eurostar is a much better travelling experience. I cautiously suggest it would be more reliable also. (My easyJet record to GVA is around 70% PPM, with the other 30% leading to a full refund if they played by the same rules as U.K. National Rail).
I’d say they could easily charge £150 one way at quiet times, £300-400 at busy times, and with the right promotion could get half the current market (and expand it). That’s over £1m per Saturday, £2m on the busy dates. Not a bad return on 4-5 diagrams of stock with 2 sets of crew each for a day (plus the access charges of course).
As ever, border control will get in the way. If only this country could grow a pair.