I just did one and I found I could do ok if I didn't try tight corners or curves, or quilt too closely. It does not move around as nicely as cotton when you try to free-motion. I used some lightweight poly batting in the middle for me daughter (in Los Angeles!) who is always cold.
I think your plan to straight-line quit would be just fine. Should look really cute!
And Tartans idea of putting the extra fleese to the front really simplifies it - wish I'd thought to do that for binding