my musher friends tell me that putting a coat on a double-coated dog like Nellie will restrict their fur from thickening out and make them even colder over the long term! That's why you rarely see musher dogs wearing coats except in the very coldest temps.

So, I have a couple of thoughts on this. Trapping a layer of air between the hair follicles and skin is how most (all?) animals keep warm in cold temperatures. Having a double coat allows for two layers of trapped air, thus providing better insulation. This is why breeds originating in cold climates hsve double coats. Nellie has spent her life in a warmer climate, so even with a double coat trapping air, she may feel uncomfortably cold. I would give her some time to adjust, but if she still seems uncomfortable with the cold, I'd get her a good jacket.

My other thought is your musher friends have dogs who are doing vigorous excersize in the cold. Running in the snow and pulling a sled is hard work. That is going to help keep those dogs core temperature up. I guessing Nellie isn't doing anything near as vigorous and likely not for any sustained time, even when she does run hard.

The new trail shoes, the Hi and Light boots, have a less rigid sole (way more pliable) than the Grip Trex. Guess I didn't make that really clear in my post about them. I encourage you to give them a try if you haven't.  

I maintain that the new boots are priced extremely poorly. It was a terrible idea to bundle two boots with four socks. To get enough boots for my dog to wear, I'm going to end up with 8 socks. I already own a set of 4 socks. It cost me about $90 to get 4x grip trex boots and 4x socks. The new boots will be $110 for a set of 4 and they'll get me 8 socks I have no use for. The only way I'm trying them is if I can find them without the socks or on a serious sale. I'm more likely to try a set of the Wag Wellies that Natalie linked recently, which come in fun colors and I can get 4 for $50 or 3 for $38.

@Jerry - last night YouTube suggested a video to me about sled dogs... one thing really stuck out to me as another key difference between Nellie and your friends' mushing dogs.  Apparently working sled dogs consume up to 12,000 calories per day to maintain their physical stamina and keep warm.  Holy shit!  That's a lot of calories.  But that might be something else to try - increase her caloric intake a bit and see if it helps with the cold without increasing her weight.  

I have no fun updates on the ramp front.  At this point it's just a waiting game for the new SUV to be ready for pick up...