I recommend that you check the weight of your hives before feeding them. Lift up the back with just your finger tips. If it is easy, then you might want to feed dry sugar. If they are heavy, I would not feed them. Everyone talks about feeding sugar water but one big problem with it is that it does not make honey, it makes condensed sugar water. The Ph of honey is around 3.6 - 4 PH, sugar water comes out around 6 PH. Most of the bacteria that attack your bees, do not like the lower PH. This is one important part of all the problems that we are seeing with bees dying, especially in winter.
Jim