I bought a pair of the Stabilicers Sport a few years ago in a size Small, which worked just fine.  I spend much of my time in Colorado, and also have a pair of regular heavy-duty Stabilicers.  They're great for walking the dog when the roads are ice or snow covered but hurt the soles of my feet when there are long stretches of bare pavement, whereas the Sport model doesn't yet still provides good traction.  Unfortunately they were stolen off my front porch (good old Wash DC) and the size Small I just received is much too small.  I don't think I had my original pair on appreciably smaller shoes/boots (did Stabilicers change the sizing?), but in any case I do know that the current size Small has no chance of fitting over my women's 8.5 Merrell Chameleons, let alone a heavy winter boot.  I liked the ones I originally had enough that I'll send these back and give the size Medium a try....

(BTW, my regular Stabilicers are an XS, also from several years ago.  They're marginally small - the straps are JUST long enough for the velcro pieces to link together -  but work very well once on).