Hello,

Here is some info I found on the web, for your garden in general
but also contains info on grass.

Do not apply nitrogen fertilizer in fall, and cut the grass to
a height of 4 cm before winter.
On a lawn that has been weakened by a hard winter, fairly extensive
brown patches will appear in the spring. These areas must be
reseeded. To prevent a recurrence, do not apply nitrogen fertilizer
in the fall, avoid walking on the lawn when it is frozen and has
no snow cover, and water less frequently in summer. In the fall,
you should water the grass enough to make it green again because
green foliage is a sign that the lawn is ready for winter.

Also it is better to seed early: take a look at
http://www.youcansave.com/youcansave/cangreenlawg.html

You can also try to contact Environment Canada:
Environment Canada
Inquiry Centre
105 McGill Street, 2nd Floor
Montrxe9al QC
H2Y 2E7
(514) 496-6851
1-800-463-4311