Having lived in many cold Canadian climates (Grande Prairie AB = -50 C in the winter...I kid you not; Edmonton AB = -30 C; Calgary AB = -30 C; etc) I vote for carpet every time. If you have never gone through a winter that is well below freezing, then it is hard to offer advice for warm flooring in a basement.

Contrary to common thought, vinyl planks do NOT like underpad. In fact 99% of them do NOT allow it. And the few that do, allow 1.2mm thick product. Not what I would call 'thermal' insulation.

If I need to warm up a basement floor, I use 6mm cork underlayment + 12mm cork floating flooring (click together). Together, they offer 12mm worth of cork (1/2"). And that amount of cork is SIGNIFICANT when it comes to increased temps in a basement.

I once had a client who lived in Northern Saskatchewan (she had to look south to see Fort McMurray). Her basement never rose above 55 F (13 C). She wanted a room where she could relax and get away for a while. She purchased 6mm cork underlay + 11mm cork flooring (10mm total cork). She painted and added some furniture. That was the totality of her renovation. The basement is now the WARMEST space in her house. It is consistently 72 F (22 C).

She says she has to turn DOWN the thermostat UPSTAIRS at dinner time before she can watch her TV in the evening. And it happens to be the quietest space she owns. She often comes home to a quiet house. No signs of life...only to find her TV room filled with teenagers hanging out and gaming!

So....carpet is YES...but cork might just be what you are after...especially for a cold basement in a cold climate.

Just a suggestion. www.cancork.com