Oh by the way i just read on the GTR manual about summer tires. It says never drive with summer tires below -20c as it will cause permanent tread deformation!
It says use winter tires in temperatures below 0c.
Tbh if you have a GTR the best thing to do is just not drive it in the winter. I used to work for a company where the guy who owned it was a multi millionaire and his brother was fairly loaded too. His also owned a stake in the company had an F430 as his daily driver, but to go down to the shops to get milk and to drive to work in the winter he had a Grande Punto. If you can afford that sort of car then you can afford a cheap FWD daily driver with some winter tyres