Okay, time for a homebrew DM to chime in -- and let some of the work I did for my own world help jgbrowning out.
On Earth, a degree of Latitude is roughly 68.704 miles at the equator and 69.403 at the poles.
I could not find my FRCS main map, and may have lost it. (Any idea on how to get another without spending $40 on a new book?) However, I can use some of the resources on the thread listed in my sig to do a few Realms map measurements. It seems that the Rheged Glacier north of Icewind Dale is some 500 miles from Waterdeep. The Great Glacier seems to be somewhat less than 500 miles of Waterdeep.
So, let us assume that Waterdeep is indeed at 45 degrees north latitude from Toril's equator as previously stated. Let us make a degree of latitude equal to roughly 69 miles, assuming a similar size of Earth and Toril. (I recall that the two worlds have similar sizes.) So, using this scale and doing some simple math, Rheged Glacier is at roughl 52.75 degrees north latitude. In North America, this would be a point slightly south of Edmonton, Canada. In Europe, I believe this would mark a point slightly north of Berlin, Germany. Toril, compared with our world, seems to indeed be slightly colder. (By contrast, the Greenland glaciers reach to perhs 60 degrees north looking at my maps. And many places well north of 60 degrees latitude on Earth are not covered by glaciers, but by forests and tundra.)
We also know that the Great Glacier retreated in Dale Reckoning 1038 (some three centuries befoe the current year of 1373) to allow Vaasa and Damara to be completely free of ice. So, Toril may be warming up.
jbbrowning, this does help you determine anything about Toril and its axial tilt?