We are arriving to the Milan airport and want to end up at Zermatt(eventually)-using the Swiss Pass to the best of our financial advantage! My son and I will be traveling to Zermatt and my husband will have to return to Milan for a morning flight back to the US. What would be the best thing to do-to entertain all of us for part of the day and then we leave him behind and we head up to Switzerland-the most scenic train route would be nice! We were thinking one of the lakes and then we could part ways.
Varenna or Como would both be worth a look for a short day trip from Milan. If you are using a Swiss pass you can validate it in Milan but it would only cover you from Dommodosola into Switzerland. You'll need to buy a separate ticket from Milan to Dommodosola which is about $25 per person one way. Buy that ticket when you are in Milan. I hope that helps some.
Are you just going to Zermatt and back to the Milan area? If yes, you may not need any kind of Swiss pass or card. The round trip fare from Domodossola to Zermatt is 53.40CHF. The least expensive Swiss pass or card will cost 120CHF and that's only a 1/2 fare card. Thus, you would be paying 120CHF for the 1/2 fare card and then 26.70CHF for the roundtrip fare. If you are going to other places in Switzerland, perhaps a 1/2 fare card can be useful.
Also, how old is your son? Children under 15 can ride free in Switzerland with a Swiss Family Card in the company of one parent with a valid ticket. You don't have to buy a Swiss pass or card to get the Swiss Family Card - just a valid ticket.