Hi Miss Meg - I live too far away to be of help but I do have lots of experience with BC's and do house sitting on a regular basis for various people. These few points may help - If possible go by word of mouth if you place your pet in someone else's home. Thoroughly check the property, for absolutely dog proof fencing, do they have young children and is your dog used to this, is it on a main road (gates can get left open) are there other animals, is it a noisy house especially if yours isn't etc etc. Also is there a car available during the day just in case your dog needs a vet and how far away is the surgery. How long will the dog be left alone each day. Do you have insurance in case of an accident /damage or will your pet be covered by their insurance.Not all people are what they seem. and look at pet sitting as easy money. Having said that lots are brilliant too so lets not get paranoid.
Professional pet sitting agencies are usually good as they have a reputation to uphold - an added bonus is your pet remains in his/her own home which is less unsettling and your house is not left empty.
My charges are all delighted to see me and have my undivided attention 24 hours a day when I stay. I keep to their routine and give them lots of play, love and long walks. (BTW I always put a slip lead on as well as their usual collar and lead just in case).
Hope you get sorted - will be interested to hear how it works out - go well.