Train travel in Italy

I don't think there is a train station in Ortisei

Your route would be
Varenna-Esino > Milano Centrale > (Verona Porta Nuova) > Bolzano then bus to Ortisei

There may be a train from Milan to Bolzano that doesn't require change in Verona.

The place to look for the schedules is the Trenitalia website: https://www.trenitalia.com/en.html. The last stage of your trip (from Bolzano to Ortisei) will be by bus. All you need to know to check the train schedule is that you will be departing form the Varenna-Esino station and going to Bolzano Bozen. Trenitalia will give you all the options. As far as I can tell, the September 15 departures are already loaded and visible. Just choose your travel date and change the departure time to something earlier than the default you'll probably see.

I think your best bet is the 8:35 AM routing that gets you Bolzano at 1:30 PM. It involves a regional train to Milano Centrale, then a EuroCity train to Verona Porta Nuova, and finally a Regional Fast train to Bolzano. Just two changes, and the transfer times are both between 20 and 25 minutes, which seems reasonable to me. Most of the other departures follow that routing, but they take longer. You'll definitely want to avoid the routings that require four transfers.

I don't know which discount would work out better for you.

Bus schedules from Bolzano to Ortisei are available here: https://www.valgardena.it/en/bus-schedule/. Check with your lodgings about which bus stop in Ortisei would be most convenient.

It is a little early to book this now, as all the trains for September may not yet be loaded on Trenitalia. That is where you will get the best price because they run the trains. Anyone else is a 3rd party travel agent.

RE senior discount. You need to get a Carta Freccia, and the discounts are off the Base Fare of Freccia and Intercity trains. If you buy advance Supereconomy tickets, 3 months in advance, the discount is likely to be less than the Base fare with the senior discount. There is no discount on regional trains, and the train from Varenna-Esino to Milano Centrale is a regional train, and the train from Verona to Bolzano may also be a regional train. You can even do it as all regional trains and the price is always the same. That is 60.90 EUR for 2.

No need to get the Carta Freccia for the Senior fare (and you cannot get the Senior fare without it).

The two of you can use the “You and Me” fare for 2 people without signing up for a special card. The price per person is the same as the Senior fare for you, but your younger wife would have to use a different fare. So for the 2 of you it would be more costly than the You and Me fare.

I plan to use those for our next trip even though we are both seniors. Much simpler than getting the Carta Freccia senior card.

Or get the Super Economy fare if available—-as Sam says, it is likely to be cheaper than the Senior or You and Me fare. But it is not available on all train types.

I haven't received my CartaFreccia card yet but I thought the real selling feature of the card was the ability to make a change to your fixed, non-refundable ticket. No!

Thanks for your help, I will wait till next month to book and probably use the me and you approach. Hoping for good weather to do a bit of hiking .