Avoiding an airport hotel is not silly at all.
For our last week or so in Italy last September, we were staying in Treviso, then drove the half-hour to the Venice airport. But there is also a half-hour shuttle bus to Marco Polo from the Treviso train station. Even a taxi wouldn't be ridiculous.
Treviso is a lovely, untouristed town with canals and bridges, plenty of great places to eat, frescoed Venetian-style buildings, interesting small churches and museums, a fish market on an island, and many pedestrian-only streets and porticoed sidewalks. Here's the airbnb apartment where we stayed: https://www.airbnb.com/rooms/23622993?source_impression_id=p3_1580306985_AcQhCHgBerl81gKI. Too bad that the photos don't show the view out the living room windows: a faded fresco of putti and some kind of sea monster on the building across the street, pretty window boxes and a rooftop garden with flowers, and then, in the mostly car-free street below, a gelato shop. Very attractive, easy, relaxing, fun, and walkable town for your last night. Do stay in the old part of town. That apartment would be a 15 minute walk or a 9 minute taxi ride to the train station.
We loved Padua even more, and stayed there for more than a week, but it is a big city and perhaps more of a transportation hassle than Treviso for just one night. Of course, if you want to visit the Scrovegni chapel, that alone is worth any amount of hassle. In September, people only got 15 minutes in the actual chapel, so we did that, but then also booked the special evening double-visit, which got us an incredible 40 continuous minutes.
