First of all right now the deer in this area are doing great because of lack of snow. That can change rather quickly though and march is a very important month for them. Alot of snow could cause major problems with pregnant does.. By not getting enough to eat and the hard walking ect.. will leave weak or dead fawns at birth.
For as far as feeding them it is not such a problem. It is predators that are being attracted to the area that the feeders are in that causes problems. Another issue we have seen is deer feeders being near highways. Being near the high ways causes alot of road kills that wouldn't normally be happening.. So if feeding keep in mind those 2 factors so that it can and will benefit the deer you are trying to help out..