] Does anyone know what ‘Napoleon blankets’ are? Was this the hysteria-driven Regency equivalent of plastic sheeting and duct tape?

Iirc, from another JA biography, the title of which escapes me at the moment, a "Napoleon blanket" was a blanket with pockets sewn onto it. The idea was that if one were forced to flee suddenly into the night en deshabille from the invading French, one might at least carry along a few things in the blanket one had hurriedly snatched up for warmth.

Why it wouldn't be a simpler and more effective precaution to hang a coat on a peg in the bedroom I don't know.