We really like the bush (we're calling it a tree, after how difficult it was to move!) and didn't want to get rid of it, so we trimmed it back by half, and after three hard days of digging and loosening roots to no avail, Ken called in my Dad and his pickup. They were able to pull the magnolia out and spare enough roots (we hope) that it should come back nicely at the corner of the house and will serve as a screen there to hide the meters on the side of the house.
Update March 25: The magnolia seems to like its new spot in the yard—it popped some new blooms today! (There's quite a hole where it used to be, but it won't be long before we have it filled in and get that area looking nice again.)