Looking for a small town stop in Northern Italy

Stresa on Lake Maggiore. It's a stop on the train from Milan to Montreux. The station is a 10 mnute walk to the waterfront and a slew of hotels.

I also concur with the recommendation to stay at Stresa - a lovely town. Be sure to give yourself time to walk the promenade, take the small ferry to Isola Bella and walk through the Borromeo villa & tiered formal garden. Also, Isola Pescatori is a cute fishing village island.

Last time I stayed in Stresa at Hotel Milan Speranza Au Lac for a few nights (friendly staff & excellent breakfast) and splurged my last night by staying on tiny Isola Bella at Elvezia Albergo in a beautiful room with a balcony to watch the sunset from the island - magical!

Another vote for Stresa. Jean gave great advice.

Check seasonal attractions for Spring opening dates, including the island gardens.

The summer ferry schedules on Lago Maggiore start on April 7th.

However, the Borromeo Islands are open on March 22nd. Isola Borromee The limited winter ferry schedule, through April 6, still stops at the islands, but not as often. Click on the Arona-Cannobio and Cannobio- Arona schedules. But be aware of the schedules, or you might end up on one of the islands for 2 hours longer than you planned.
Lago Maggiore ferry schedules

Get a "free circulation ticket" that allows you to get off/on the ferry in any order if you plan to do the Isola Madre, and Isola Bella. If you get an early start, you could also go to Villa Taranto Gardens in Verbania (directly across the bay from Stresa).

Another thing that will give you spectacular views is the tram up to Mottarone