What size of crate do you have? You could get the biggest size of wire crate they make (for great danes, etc.) so the dog would not feel so enclosed when you are gone. If you have a backyard, you could leave the dog in a large dog run while you are away. That is what I do with my husky, he is inside when i am home. Of course I've heard shelties can be barkers, so you will not be able to do this if the dog barks constantly..don't want to upset the neighbors!