Is the commute from Padua to Venice "do-able" on a daily basis?
It’s not a long train ride, only around a half hour.
Make sure to ride the Regionale Veloce trains. They are express and take 1/2 hour. Others make lot of stops and can take 50 minutes or more. Same price.
Yes and no. It's possible, but it means long days without being able to pop in to your room in the middle of the day for a rest or to freshen up before dinner. It also means a lot of travel time every day. It's a 1/2 train ride, but you have to get to/from the Padua train station which can take another 1/2 hour (or more in the evening if you have to wait for a tram). Then you have the time to get to/from the Venice train station. For instance, it's a good 1/2 hour walk from San Marco (more if you get lost) and closer to an hour by vaporetto.
Been to Padova 2x--Once as a daytrip from Venice and it was an easy trip. Would I stay in Padova and do daytrips to Venice....probably not. Would rather stay in Venice.