Found
a pair of the Trail Crampon Pro's under the tree. Only aerated the front yard so far. Might get a chance to try them "for real" tomorrow.
The regular size fits (but just barely) my size 11 1/2 Keen County boots.
The "Alpine Stopper" thingies are a bit of a concern - I hope they aren't necessary, since I can't see handling those in the snow with gloves on and not simply having them disappear forever the first time they get dropped in a drift.
Also, with the 11 1/2 boots, I don't have a whole lot of strap sticking through to stick them on. As far as I can tell, no local retailer stocks the XL, so I can't tell if the larger size would give a better fit.