went via DL jfk a few wks ago. most flights are stable within 2 week for exact dates. the crew hotel is ambasciatore and is right across street from #4 bus $1EU/pp to Venice. The area is called MEstre and they have a very nice Christmas market there.
prices in venice can be outrageous and hotel nr rialto or on canal are $$$$$$
ck out the DL discount here: requires ID:
accorhotels.com
ck box for company contract box left side
SC006924872
code 32474
There is a Sofitel right by the bus station and vaporetto (boat transport). Accor is also Mercure, Novotel, etc.

there are 2 best western )privately owned in good location
venere.com is one of the best sights for eu also try hotelclub.net they offer good prices and you accrue $ to use next purchase

good luck--come back if you need more help