Anywhere high enough to have snow at Easter but still short transfer time?

Depends what you class as short. In general, the taller the mountain the better the Easter snow, but tall mountains hamper airport construction somewhat. You'd be looking for somewhere with high altitude or a glacier, or alternatively look up in the Scandi resorts. Hintertux and Stubai are within a couple of hours drive of Innsbruck with glaciers, and Ischgl is high altitude too. Are in Sweden is less than an hour from Ostersund airport, Levi and Yllas in Finland are less than an hour from Kittila.

I would say Montgenevre (one hour from Turin) or Flaine (one hour from Geneva). Both usually very good at Easter.
We booked both holidays through Ski Collection who I'd recommend. We went self drive but they offer a discount for people booking their own flights.

Belle Plagne is 2 hour 30mins transfer

Alpe d'Huez, Les Arcs, Kaprun?

Easter is late this year. Sass fee.

Saas Fee or Zermatt good if you can fly to Sion but otherwise 3hours plus from Geneva.

Ischgl, Obergurgl, Hochgurgl

obergrgul.