I just put mine in the garbage yesterday after 7 years of abuse, they use to be the best insulated rubber boots on the market, but they move the production to China a couple years ago and the Chinese version are not even close to be any good. Up here and in Alaska, that is what people wear almost all year around. In south east Alaska, our neighbours, they call them Juneau(Haines, Skagway) sneakers, they literally wear them every day!! And some friends told me that they are lucky to get a full year out of a pair since the move to china!! So unfortunately, I wouldn't buy a pair of these anymore!!
As for the fit under the seat, I wear a size 13+ boot and insulted, and never had a problem kneeling with my feet under the seat!!