Ugh. I'm sure you know more about frostbite than I do. Thankfully, I've never experienced it. I Googled around a bit but didn't find anything that said much beyond what you've already noticed. Here's one link I found, but it's pretty basic. Says ears are definitely at risk.
Oh, and sorry for calling you Jenna!
Frostbite on Dogs
__________________
Mike ~ Doting Dad to Jillie, Harper, Molly, Cooper, Eddie (RIP), Lucy (RIP), Rusty (RIP) and Jack (RIP).
Check us out on YouTube