We are considering a month stay in Bergamo in September 2020. Our goal would be to have a 2 bedroom 2 bath furnished apartment in Città Alta for the month of September. Could someone offer some suggestions Regarding this request.. Thank you in advance.

Suggestions of an apartment? Or....?

Personally, I like Bergamo, but I don't think I'd want to stay there for a month. Will you have a car?

I'm not sure you were asking for comments...

You probably won't want my comments, either, but much as I'm fond of Bergamo I wouldn't want to stay there for a month, either. Is there a reason you've zeroed in on this location?

If you're determined to do this, I'd contact the tourist office. They almost always have leads on locals who have places to rent out. Otherwise, use booking.com and use the filters to narrow down what you're looking for?

I don't think Bergamo is very convenient for the excursions you mention. You could make multiple trips to Lake Como to see different things, but a single day trip won't give you very much time if the sights on your list are scattered around the lake. Same problem with Lakes Maggiore, Orta and Lugano, but the fastest driving route is boring and not one I'd really want to do multiple times. You can reach the southern end of Lake Garda within a reasonable amount of time, but it's a big lake and, IMO, the best parts are at the north end which would take more than 2 hours to reach by car.

As for trips to Switzerland and Austria, would you be going to places for a couple of nights? Otherwise, places that immediately come to mind, like Interlaken, St. Moritz, Luzern and Salzburg would take 5-9 hours to reach by train. You could take an overnight train to Vienna, otherwise look into flying nonstop from Bergamo to Vienna. There's at least one airline that operates that route. Lauda Airlines.

With what you want to do, it might be better to stay in two places. One location for the lakes and another location for the Switzerland/Austria part of the trip.