...the layering system, such as you use, works really well when it's actually cold, and is comfy even when it's even just a little chilly.

Unless you need to combat cold without a constant central heating unit, you might not use the layering, but when you need it, it's great.

I, too, have a hodge podge of layers, and each has to be in it's correct order for maximum warmth, and also comfort.

Yes, you have that additional problem of the open space under the house.

Stay warm!