I just use a nice funny sock with the top cut off, hehe
And for 'waterproof' (for showers), my nurse told me to use cling film.
So much cheaper than buying purpose-built things...
It is the circumference of your arm/bicep that you should measure. I got the waterproof one on prescription from the GP but the chemo unit had to request it.
Picc line does not hurt. All you will feel is the local injection just above the inside of your elbow then it all goes numb. They have to send you for an xray to make sure it is in the right spot - mine was and everything was fine. It takes a few days to get used to it and I have bout a couple of covers from here:
With drinking, just be sensible because one nurse told me that someone went silly and diluted all her important levels due to excess drinking. So about 4 pints all day or there abouts, enough to keep hydrated and dilute the nasty stuff.
Since you are cold capping I would take a flask of something hot because that can be a comfort.
Let us know how you get on xxx