I live in New Brunswick and have the very same complaint about the Bridgestones (215/70/16) on my 97 RAV4 L 4dr auto. Terrible in the snow, and need replacing at 48K. I tried to order a more aggressive tire in the Dueler AT 693 which looks very good and is supposed to be great in the snow, but I came to find out that Bridgestone cannot supply them for 5-6 months.
After checking with most major dealers in the province on what they had in stock in my size I settled on the Michelins. I don't suspect that they will be spectacular in the snow but they should be much better. They have been on order for 4 weeks and Michelin was supposed to deliver to my dealer last week, but not a word yet. Not one single dealer had anything other than OEM Dueler & Dunlop(which looks as bad).
There is a Toyo dealer that I can see from my office window, but I was going to pay $20-40 more per tire than for the Michelins as I went to inquire after reading your posts.
I am assuming Toyota went with this odd size to help with ground clearance, but it sure makes it difficult on us owners.
I'll post my opinion on the LTX M/S after a bit of winter driving.