If you don't see a winter tyre in your size, try setting the Speed Rating and Load Index to 'Any'.
All tyres are rated for the maximum amount of speed And weight they should carry. But winter tyres have a lower speed rating than summer tyres.
For example your current summer tyres may be V rated (max speed 149mph) but the equivalent winter tyre Is H rated. An H rated tyre still has a maximum speed of 131mph, more than enough for winter driving conditions.