Oooh, that's an idea. When I go to make my purchase I might ask if they'll let me do just that . Yeah with the loosening up considered, I was edging towards the 50. Also it had the insert liner thingy you could take out for summer, which frees it up a little? Plus my cut continues... maybe factor that in... xD.
Cheers for advice though, liking the sit-on-a-bike-there-with-it idea.