Airports for Tuscany / Grindelwald Vaction?

We used Milan MXP when we went to Grindelwald and often use it when we are going to Tuscany. I recommend you use it too.

if you don't want to fly within, to Tuscany I'd suggest Pisa or Milan and then train to Florence.

Multi City or Open Jaw

Train to Grindelwald, probably via Milano Centrale, then Spiez, Interlaken Ost, Grindelwald.

Fly home from Zurich with a possible last night in Luzern.

one of several choices, but presuming these should work from at least one NYC airport

There are direct non-stop flights between New York and Milan on Delta, Emirates, United and Lufthansa.

There are direct non-stop flights between New York and Zurich on Swiss and United.

Zurich would not work as a round-trip (too far from Tuscany) but it might be possible to book multi-city into Milan and back from Zurich on United.

However, my personal choice would be Milan round-trip with either Delta or Emirates, both airlines I like.

You are going to have to travel from Tuscany up to Switzerland in any case, and it is a nice trip by train, so the return trip to Milan for your flight home is not burdensome. After the wedding festivities, take the train to Luzern and spend a night there (or in a nearby town on the lake for a nice relaxing stay). Then the next day take the train to Milan—all trains should be running over the Gotthard Pass route until September, so you will have a nice journey.

Or you could travel from Grindelwald as far as Lugano, 2.5 hours past Luzern, and overnight there. There are direct trains from Lugano to MXP, taking 1.5 hours, so you go straight to the airport without a night in Milan if you wish.

Thanks all for these great suggestions. I had thought of the train ride from Tuscany to Grindelwald as just transport, wasn't even thinking of how beautiful it will be.

I'm curious about whether we should try to stick to the northern part of Tuscany so we are closer to Switzerland or if we should be more open to going to various parts of Tuscany both north and south. New to this forum. Should I post that as a separate Italy question?

For Florence Rome would also be an option as an airport to fly in to.

I would suggest that indeed you fly in to either Milan or Rome, and back from Zurich.

One tip: Currently there are no midday EC trains over the Simplon route, so when travelling from Florence to Grindelwald you will unavoidably arrive rather late, unless you take the detour over the Gotthard.

The other issue is that on the Gotthard the base tunnel got damaged by a derailment. So most trains now go over the old route, which takes an hour longer, but is more scenic. As the repairs progress the railways plan on sending more trains through the base tunnel.
On the SImplon route there are also a lot of engineering works going on, so on some days the schedules are different. and on other days trains leave from Milano Garibaldi in stead of Centrale.

All this means that reservations for those EC trains often open later than is usual. So my suggestion: Don't jump the gun on train tickets. You can safely book these trains only a few days out, or a few weeks out to get a good price. If you try to book the trains and you see no EC trains offered, wait a bit. That just means they have not been loaded in the system yet, as the schedule has not been finalised yet.

Yes, you will get more responses if you post that as a separate question in the Italy forum.