I'm in Minnesota, and have used the Farm Innovators one you linked for two winters. I can attest to the fact that it kept water fluid down to -34F. There was ice in the bucket, but mainly just the top 1/4" of water was iced over. The nipples were still flowing water easily when pecked. The first winter it did great, but last winter I ran into an issue with it failing. As the hens peck on the nipples, some of the water drips down the side of the pail and somehow manages to weep into the heated base. When enough water ends up in there, it shorts out the heating element. I found the waterer frozen on two occasions. To fix it, I removed the base, cleaned out the water and dried it, then removed and cleaned the element contacts. Once I did that, it was good to go again. This happened twice on me. But other than that, it performed beyond expectations. I can't use it this year, as I have a blind hen who cannot use a nipple waterer, so I am going to use the Little Giant galvanized fount waterer on a heated base. I'd much prefer the nipple waterer.
A few other things I like about the Farm Innovators one:
1) It is opaque. That makes it really easy to see the water level and know when it needs to be filled.
2) The lid can be removed without having to remove it from the hanger. This makes it really easy to just take a pitcher of water out and fill it in place.
3) It only draws 65 watts.
For my issue with water getting into the base, I think I can resolve it by simply using some silicone to seal the base and prevent water from weeping into it.
I was looking at the Premier one for this year, before I knew I had a blind chicken. I liked the removable cord feature, but didn't like the fact that you have to remove the waterer from the hanger to remove the lid. That alone makes the Farm Innovator one way better. I guess it would be fine if you didn't hang it. You also can't see the water level without feeling how full it is or looking.
All that said, If not for my blind chicken, I'd be using mine for a third winter, since it has proven itself to me at temperature I thought it would never handle.