A quick follow-up from posts earlier today.
The failing furnaced was "red-tagged," which means the furnace is done! No reviving it. It was emitting both gas and carbon monoxide.

A crew is coming after work tomorrow to put in a furnace. They will work as far into the night as it takes to finish the installation. It surely helps to know the company boss/owner.
I have two area heaters going on each level of the house. I am a little leery of them. They are "bare bones" heaters. I am going to all levels, 1-3 to check on them. every 3 hours or so.
thanks for the support earlier today!
Much Love