Late night arrival in Venice

The last five ATVO airport buses depart Marco Polo at 22.20, 22.50, 23.20, 23.50 and 00.20. You do have time to make a bus to the Piazzale Roma. Make sure that your hotel is aware of your late arrival. Should all of that not work, there are two hotels at the airport that I would suggest looking at. 1) Courtyard by Marriott. It's just across from the airport entrance. 2) Titian Inn Hotel & Residence. But, you can easily make the bus.

Ditto Larry. Just make sure your hotel knows you are coming late and can check you in at that hour. Smaller places, particularly, don't always have a staffed desk at late hours. And unless they're specifically told that you'll be arriving late, many hotels will assume you're a no-show, and give your room away (usually charging you at least one night anyway). I certainly wouldn't spend my first night at an airport hotel in your circumstance. Just get to your Venice hotel and crash there.

and you can always grab a taxi which will either take you to the watergate of your hotel or very near. Ask your hotel if you can arrive late.

As an alternative: I also arrived late (although not quite that late) and didn't want to deal with dragging my luggage through venice in the dark, hoping to find my hotel. I took the airport bus to Padua and spent my first night there (which allowed me to have a taxi drop me at my hotel). I had the next day to explore Padua (Giotto frescos, the cathedral, univeristy, etc), and then headed to Venice in the evening. It was a relatively relaxing arrival, and much easier to deal with than a jet lagged exploration of Venice in the dark.

Be warned: Water taxis are extremely expensive.

Water taxis are 90-110 Euro for up to 8 people with luggage.