Great information!! (as always)
I do lots too. Like wearing goretex inner shirts, pasting hot patches inside my jacket (actually I use 6! Two big ones in the back, one small one on each side of the front and one small one in each side of my jacket pockets). I also wear neck covers too.
Sometimes I even stuff my gloves with small hot patches.
But never tried drinking a lot....I'll be afraid to think of all the loo stops I'll need.
But staying warm is a really important topic if I want to ride duirng winter. It's not safe either to ride when your whole body is stiff from being cold!!
And I do layer up....sometimes so much that I feel like humpty-dumpty.