Hello. I am sorry but not able to give any advice on anything you ask - sorry - but thought I would reach out with a virtual hug.
We have a date in common - my mascetomy with immediate reconstruction is also happening on January 7th. My sentinel lode biopsy is happening at the same time as that rather than before like yours is.
I will be thinking of you and am here for you and hopefully will be able to share some top tips on this as we go through it together.
Sending love 
and so thought I would reach out and give you a virtual hug.