Quick Question - Andermatt to Stelvio

I'm off to the alps for a few days on Wednesday. I've pretty much got my route sorted but one thing I'm not sure about is whether I can make Andermatt to Stelvio and back in one day. Tried looking at the maps and it seems to be about 300 miles round trip. Would be a shame to go all the way there and not do Stelvio as its my first trip, so any thoughts appreciated.
Day 1 is Albertville to Andermatt taking in Col d'iseran and Roseland. Day 2 is furka, Grimsel, Interlaken, Susten and back to Andermatt. Day 3, at the moment, is back to Albertville and heading up towards Le Havre for an overnight stop before catching the 3.30pm ferry. Thanks

One more quickie - do i need to take my inner linings for jacket/trousers? Weather forecasts seem to be between 60 and 75? never been before, as you can tell...

Andermatt to Stelvio is a helluva ride via Chur/Julier Pass to Livogno/Bormio and back and I would say although technically anything is possible...............300 miles on those roads is a no-no from my experience.

The Stelvio is a famous pass, but by no means one of the best

Do it another time when you're in the area or alternatively don't stay in Andermatt

Take the linings or it's bound to rain............

I'd say it'd be a long day, but manageable.

A couple of weeks ago I rode from Chur in Switzerland to Arabba in the Dolmites via the following passes (about 330 miles I seem to remember):

Lenzerheide
Albula
Ofen
Umbrail
Stelvio (down and back up)
Gavia
Mendel
Sellajoch
Pordoi

A great days riding until it started p*ssing it down as I reached the Dolomites.

From Chur to Stelvio took about 3 hours at a leisurely pace. The Lenzerheide, Fluella and Ofen passes are all smooth, quiet (and great riding) roads and make reaching the Stelvio a doddle.

The Stelvio isn't much fun to ride, but is awesome to see and a must do for any motorcyclist.