Finally made a decsion to stay at the Hotel Campiello. Thanks to everyone who gave it good reviews. Now my question is 1 night or 2 nights in Venice. We will be arriving around 1pm or so and can stay most of the next day.

I would stay 2 nights. The evening is the best time in Venice. Music in St. Mark's square and riding on the canals with the lights are truly wonderful.

Three.

I vote for two nights. Otherwise you don't have one full day in Venice. If you are traveling both days, you miss the experience of being without cars for any length of time. After five days in Venice, it was jarring to get in a taxi and go to the airport. You feel somewhat removed from real life and the rest of the world. I don't think you'd get that experience if you arrived one day and left the next.

I also agree with 2 (3 even better!).

As many nights as possible! Venice is very special and different. The longer you stay the better.

For sure two nights, and if you can change your plans, try for 3. It's magical.