I hope you have some time to think this through. I know coming to your Mom's aid in time of need is the best thing you can think of at this point but it doesn't sound like a good fit for what you have going on in your own house.
It may be better for Mom to stay in an extended care facility up there and have your Sister, if closer, take care of any personal needs.
If the Shepherd is as good as you state, there should be a means to have him housed and to visit Mom on a regular basis. My Daughter is a pet caretaker and I would assume there are those in Winnipeg. If I was closer, the dog could be here.
Hope it all works out for you and your Mom.
