Is adding more work an option? When things are slow, once everyone gets done for the week hand them a box of doorhangers to go do some promotion. Surely you will need all the help again this fall?
Yes I am also going to try upselling a little bit in the next few weeks. I'll probably send an ad out with my next billing and try calling a couple good customers who may be willing to give us some work. But fall is a big concern for me, because we will be very busy again.