It gets cold in the mountains and I am kind of a stay warm freak. Here is what I do to stay warm, It might be extreme for some.
1) Body heater suit, I have two. I have KOM wool, this that. Nothing compares to the suit. I do not like the bulky clothes on either. I bought a cheap fleece vest and sewed pockets in the vest. Two over the kidneys and one in the center between your shoulder blades. The suit has a knapsack you can buy with it. I highly suggest the knapsack.
2) for my feet, bunny boots, mickey mouse boots, what ever you call them.
3) Next to my skin I layer merino wool, put my vest with large hand warmers in the pockets I sewed then put it in the knapsack with my heater body suit.
4) head, I just use a warm wool or polarflecce hat.
I walk up the mountain climb my stand, then put my body heater suit on then the vest and maybe a wool KOM bowmen jacket if it is bitter cold.
sometimes I will sit in the stand in the dark and cool down from the climb before I get dressed. The best way I have found to stay warm.
I will have to try the tea deal , never tried to drink.