Zermatt and Val d'Isere are the clear cut top two resorts in the Alps for spring snow preservation. Val Thorens is pretty good too. Chamonix is not as good as it would be with the Grands Montets upper tram running. I have not yet seen a projection for when it will be rebuilt, but it won't be for the upcoming season. Dolomites are average plus for snow preservation but extremely erratic for snowfall so you have to see how the season is developing before making a call there. That said if your wife is going with you Venice plus Dolomites is an attractive option to keep in mind. Who if anyone is going with you?
Do not let the Ikon determine where you ski in Europe! We were there in your exact time frame in 2022 and used the Ikon one day at Cortina on our way from Venice airport to Austria. The southern Alps had a horrible season, which is why we didn't go to Zermatt. And Cortina was so limited that the walk up rate would have been something like $27. Average full operation window lift tickets are still in the $75 range in Switzerland and $65 in the other alpine countries.
Most of the Austrian places have low base elevation and many of these have bad exposures too. As noted Kitzbuhel is really low and not a good idea at all. You could go for the Austrian glacier areas but overall they are smaller. Look at our TR's from last spring. We made 4 days in Austria work, but aside from the Pitztal Glacier the snow was much better in Val Thorens.
Give that time frame I strongly encourage you to follow our well proven strategy: book your plane ticket (I'd lean toward Geneva for proximity to more of the high altitude places) and car rental in advance and start thinking about resorts a week or two before arrival.
Yes Easter week is a factor for crowds in some places. I've seen it at the end of Easter Week in Val d'Isere in 2018 and the beginning of that week in 2022 at Les Arcs/La Plagne. All of the British schools and some of the French have that week off. Those big French ski complexes have a lot of lift capacity and far flung sectors with lots of elbow room, but it can be an ant farm near the base areas.
Switzerland by observation is least affected by school holidays. Zermatt would be a good choice for Easter Week if they get enough snow, which you will hopefully know at least a month in advance. Late March before Easter week I'd lean toward the Tarantaise complexes, with Val d'Isere/Tignes first choice, Val Thorens second and Les Arcs/La Plagne third. Portes du Soleil is interesting and very close to Geneva but overall too low altitude for spring most of the time.
