Do you not water at all over winter? Do you think they will survive in the shed?
The cooler the over wintering conditions, but not freezing, the dryer the plants need to be kept for them to survive..but not 'bone dry'!
There have to be tiny amount of moisture for the roots to survive. Trouble with sheds are that they tend to be too damp, dark and cold so unless you happen to have shed with little heating that keeps the air above freezing temperatures and the air drier and some natural light coming in.
Over wintering in house is perharps easiest, unless you have heated GH. But how much to water?..you just have to judge by how the plants 'behave'..given enough warmth and moisture and they will attempt to grow, but with the light levels being so low during winter, unless you have grow lights, it is not ideal time to allow them to grow as resulting growth will be very spindly.
So the idea of keeping them 'almost dry' is holding back the tendency to grow.
Saying that..I had one chilli last winter that just wouldn't settle for 'hibernation'....so I ended up watering it and it kept growing lushly all winter and everytime the light from the window got blocked by the huge amount of foliage....I ruthlessly chopped it all back and it started the growth all over again..
Some growers prepare their plants for wintering with root pruning too as well as tops. Last year I didn't I just kept the plants in their pots as they were. This year I have that many plants to over winter that I'm going to chop the roots..it allows me to pot the plants into smaller 1 litre pots saving lot of room and same time changing the compost into 'fresh', pest free 'bedding'. When pruning roots you do have to prune the top growth very heavily. There is good advise how tho prepare plants for this way...
http://fatalii.net/growing/index.php?option=com_content&task=view&id=95&Itemid=105 It is for chilli bonsai, but works well for over wintering and when potted on 'as usual' in spring, the plants carry on growing normally. It is just a way of keeping the 'stools' alive and stored over winter.