That is exactly how I quilted with minky as a backing. It's the least stretchy direction of the minky. I did not use spray basting and did use a batting. It's also how I quilt with fleece as a backing.
I made sure that the minky was not stretched out by the side leaders I use on my long arm. I used a medium density edge to edge quilting pattern. The quilt came out well.
Good luck!