Early morning flight from VCE Marco Polo - should we stay at an airport hotel?

You need to get an early start. Here is the bus schedule: http://www.actv.it/pdf/urbano/U-5.pdf
Mon to Sat there is a 4:35 bus from Piazzale Roma and a 5:40 bus.
Here is the vaporetto schedule: http://www.actv.it/sites/default/files/ultimorario.pdf
You can take the N boat to get to the 4:35 bus, and the 1 boat to get the 5:40

We will be flying out of Venice in June and we have opted to stay at the Antony Hotel in Mestre that has a shuttle service to the airport. It apparently is only a 5-10 minute drive to the airport and a 20 minute bus ride from Venice itself.

Where are you staying? It would help immensely if we knew the hotel as you have different options depending on where you are staying. The airport opens at 5:00am. First bus from the Piazzale Roma (ACTV No 5), departs at 4:40am. The second bus (ATVO) departs at 5:00am. Either will get you to the airport in plenty of time to check in. Now, it depends on where you are staying to answer further on how to get you to the Piazzale Roma in time to catch one of these buses. If you were staying at the Hotel Papadopoli, you would simply walk 500'. If you are staying in the St. Mark's plaza area, different story. You may need to take the night vaporetto that comes through there at 3:40am. Please advise.

Wow, lots of people know the bus schedule from PR to Marco Polo!

Note that if you decide to take the early morning bus from Piazzale Roma, buy your tickets before that morning as the ticket office is not open and I don't think you can buy them on the bus. So as not to ruin your last day in Venice with worry that you won't make your flight, I'd vote for a hotel at the airport or one that will guarantee a shuttle early in the morning. And enjoy. And next time, ask for a flight at noon or later.
One last thing: on our last flight we had to take one of the earlier buses (say 7 am ish) from Piazzale Roma to the airport.--we always get to the airport way early! The apartment we rented was a 15 minute walk to PR so we set off in the dawn pulling our bags and we saw a Venice that we had not seen before on our previous visits and it was worth it. An army of cleaners sweeping the fondamente, campi, and calli with huge brooms right out of the middle ages! One man repairing his huge curved broom with new straw. Quiet, alone, it was a wonderful walk, quite unforgettable.

Thanks for the replies!
We haven't booked a hotel in Venice yet... I was kind of waiting to figure out the airport situation because that will determine the length of our stay (one less night if we stay at an airport hotel). I've been looking at some apartments on AirBnB, as our budget is a bit low (ideally, $150/night) and hotels seem to be way out of our range.
It sounds like there are early morning options to get to the airport. Is there one area of Venice that would be better to stay in than others to make these options work? Or would the peace of mind of an airport hotel be worth cutting our time in Venice short?
I really appreciate the advice!!

There's a Courtyard by Marriott over at Marco Polo Airport area for 105 Euros.

If you go to GoogleMaps.com for Venice Marco Polo Airport and click on the + three times, it will magnify all the area accommodations. Click on them, and you can see their internet link. Some hotels are reasonable in price.

It's not necessary to stay at the airport but you certainly can. One hotel that I can recommend to keep you in Venice is the Hotel Santa Lucia. It's near the train station and it's well within your price range. It's an 8-10 minute walk from the hotel to the Piazzale Roma. The issue is getting from where you are staying to the early buses. Daytime vaporettos don't begin until just before 5:00am so that's too late for the two early buses. But, there is a night vaporetto. From the St. Marks area, it's a 35-40 minute ride on the vaporetto. Thus, you have to catch the 3:40am night vaporetto at St. Marks. It does stop at the Piazzale Roma.

Or, from the Hotel Santa Lucia, it's an 8-10 min walk. True it's at 4:15 in the morning but it's not a long walk. You go right in front of the train station and over the new bridge over the Grand Canal. Here's a screen snapshot of what the walk looks like. http://gyazo.com/f80ebdb27e6f11c1b255cd02395c7166 Enjoy your last night by staying in Venice.

As a side note, you can buy a vaporetto ticket + a one-way ACTV bus ticket to the airport in advance on www.veniceconnected.com. Thus, you will have your airport ticket in advance.

Larry, thanks for the very detailed directions! I think we'll take your advice and stay in Venice our last night. It will be interesting to see it empty of tourists on the walk so early in the morning, as krisbean said!
Thank you for the thoughtful advice, everyone!

We just stayed at the Hotel Santa Lucia in May and even though it is near the train the area surrounding the hotel is quiet. The hotel has a lovely outside garden and tables with umbrellas for outdoor seating. Tricky to find-down a long corridor of buildings (you pass a small bar that has great snacks). Not fancy but very clean and the hosts are nice. Loved sitting outside and having a glass of (our own) wine. Linda