Perfect, with or without storage. Also much easier than my setup, which was inexpensive and works well, but is a PITA to get in and out. I can't have humans in the back seat or even vacuum without a lot of work. The one advantage of mine is that the whole area is covered so the dogs don't see the distinction, but that could be done with the Orvis blocks as well.
Jan - I had much the same setup in my '02 Impreza, which was even smaller than the Crosstrek. Betsy and Edie used to ride there together without much trouble. I think I even had Perry, Minnie, and Betsy there for hour-long trips. There's probably a pic locked up in Photobucket.