I have a few in my garage too although most of them are already in pretty sad shape so I try and work up the best of them first and bring them in as I can. In the winter I run the wood stove out that when I'm working and in the summer I open the door and run a fan both to make it nice for me to work AND to help control the temps for the sewing machines.
If you end up with too many it's all you can do! *Really, can you ever have too many??