Hi & Welcome,
I was wondering what kind of shows you are looking to attend ?
If its Open or Champ shows do you have a local ringcraft class ? Someone there might be your breed / group or a group on the same day as you. Also, you could try joining the national / local breed clubs for shelties and ask around there (some have internet notice boards).
If its an agility show then you can put your request on agilitynet for free !
I hope this helps – there must surely be more Sheltie/Group/Same Day people in your area and I am sure in this day and age the help with petrol would be snapped up too !! 🙂
Another idea I had was if you went to a few shows by train (maybe have to be without your dog) and got to know exhibitors that go on your days it might be another way to find somebody too ?
p.s. Good Luck with the showing 🙂