Lake Orta to Sardinia

I would suggest taking a train into Milan and it is a major hub in Italy to fly from their airports.
I have not been to Sardinia - but I'm sure you can connect from Milan.

At the end of my RS Village Italy tour some of the folks got together and hired a private
car/shuttle to take them into Milan. Since I stayed 2 more days at Lake Orta (I loved it there),
I took the train back into Milan......it did require one train change.
But this was a few years ago and I'm not sure what the current train schedule is.
I hope you enjoy the Village Italy Tour - it was one of my very favorite RS tours.

Where at lake Orta? Omegna? Pettenasco? Orta San Giulio?
You need to find your way to Malpensa airport. By car it's less than one hour (just drove it last month).
By train the fastest way is to get to the Verbania station (lake Maggiore). There is a bus from Omegna to Verbania. Then you take a train to Milan, but you get off at Gallarate. At the Gallarate station you can take a taxi to the airport (10 min) or a bus.
From Malpensa there are several flights to Sardinia's airports: AHO and OLB in the north, or CAG in the south. They are flights with low cost airlines (Easyjet) or Meridiana.
No flights from Sardinia to the US. Got to go Rome.

@Roberto....Orta San Giulio is where the tour ends. Thanks for your insights, they are always helpful. We may end up spending a couple of days at the lake before going to Sardinia. But I do have a problem with the end of the tour traveling to Lake Orta, having a quickie tour, farewell dinner, sleep and then ???????
Don

Not much to do after you've seen Orta San Giulio and maybe the island. It's just a quaint village that is nice to visit and relax at a bar in Piazza San Giulio.
If you stay a few days in the area, you may want to go to lake Maggiore, just minutes away across the hill. From Stresa or Verbania you can visit the Borromee islands. Further north is pretty Cannobio and also Locarno (CH). Once you get to Stresa or Verbania on the lake, the main towns on the Piedmont side, you can travel around the lake by boat or bus or train.
You could even travel on the Ferrovia delle Centovalli from Domodossola to Locarno on the FART train (which in spite of the name, doesn't stink at all).

Thanks, all.

Thanks Frances and Roberto.