Thanks for the suggestions all
Pretty much all common sense I know, but it helps to see em in writing.
35F, I fed her some more sausage this morning, slipped the dish under the blanket as I usually do when its in the 40's or below and she ate it, was not shivering. That hot rock generates a toy-dog sized warm spot under the blanket. The one I used for the past couple of years (barely broke feezing) broke for some reason while sitting unused over the summer, so I doubt their durability.
A heating pad and the hot rock as a fail-safe for either one going on the fritz sounds doable. The light bulb coffee can idea sounds like an easily-doable stroke of genius, provided I can find an incandescent bulb.
Birdwatcher
