Do you ever really get used to cold weather?
Absolutely. Just like you can get use to hot weather.
That's why in Miami when it is 63 degrees in January and the natives are bundled up but the tourist who flew down from -3 degree weather are wearing shorts. The bodies are accumulated to different temps.
Or in late Sept when the tourists are complain it is unbearably hot the natives are calling it a relieving cool spell.
The coldest I have ever been was scraping ice off the car at the airport after returning from a week long vacation in Florida. My body had gotten use to 90 instead of zero. That was hardly the coldest night of the winter but it felt like it to me. Within a week my body was to normal and I was X-C skiing the following weekend.
Tough to get accumulated to the cold in just two days. But I would try and do some of that.