I can't really see a realistic way around having this discussion that doesn't fall into the "head in the sand" category. And you can't live that way, despite the current realities. And if he is also on the mortgage, I really think you have to chat.
And while the discussion will likely fall into the R category, it's not the real intent of the conversation, and I think (hope?) your H might see that. The intent of the conversation is a logistical one, but it brings the R into the light.
If you moved, would you consider relocating into a different town/area? I was guessing not because of the girls and their school and life is rooted where you are. But perhaps that's not true, so I suppose it's something to consider.
Would you downsize at all, or consider it? Would you be wanting to have a different layout or yard? I guess if you can see opportunity in a new home that suits your lifestyle that would be important.
It had sounded like your H had said "after the holidays" to have this chat, and here we are. I think it makes sense for you to bring it up. Even that first step of, "I suppose now that the holidays are over we should sit down and have a discussion about the mortgage deal. When would you prefer we do this?" which will give allow him to A) make a decision on the timing and B) Prepare for the discussion without feeling like he is thrown into it unprepared.
