Doglog680-Welcome!
You might get some ideas if you do a search under mileage runs, a lot of us in Aug-Sept got in on a fantastic fare to VCE and there are hundreds of posts re VCE. There are also some recent posts under this subgroup and a few flyertalkers who seem in love with Venice. Hopefully, they will offer some help.
You are going during a season that I would much prefer to the hot summer. I was to Venice in April and it was lovely. If you decide to get a car you could tour Palladian villas. Not sure if they are open seasonally.
Chowhound.com has an international section that might have some restaurant ideas in Venice. Save up for the gondola ride.