Don't mean to go on, but you do say that your new to sheep, so its hard to assess your knowledge base. When their shorn their clipped back to pretty much no fleece, so would be the same as you going outside naked. That might be fine on a nice day but overnight your likely to get hypothemia. If you have horses think of the sheep in the same way. I'm sure you wouldn't dream of turning a clipped horse out unrugged would you? Speak to your shearer, discuss what your planning to do and see what he says?