My wife and I will be spending a few days in Venice over the Christmas period. We are concerned that many restaurants will have restricted opening times and we would like to know where the nearest supermarket is to St Mark's Square so that we can stock up with provisions for our hotel room.

http://shops.venicexplorer.net/index.php?hlangs=en is a good site which will give you a list of (all) shops in Venice, mostly of the tourist variety but there are others listed. We are going for the whole of January into February, so need shops that supply the more nuts and bolts of life! I know scrolling through that I saw a Billa supermarket in the Dorsaduro area and also one in the Castelreggio area. So, if you Google "Billa supermarket Venice" I think that you will find somewhere. The on e in Dorsaduro will probably be yhour closest one.