Hi and welcome,
The only reason to be careful about how much alcohol you drink is the additional effects on your liver. TKI like imatinib (Glivec) are all metabolised by the liver and so puts an additional strain on its ability to detoxify efficiently. In my experience, most people do cut down- although there is no reason to cut it out entirely, unless you lose the 'taste' for it- I know I just did not like wine, beer or any kind of alcohol when I was taking imatinib.
If after a while your liver enzymes show a rise (your doctor will let you know if this happens) then you know to cut back or stop entirely until your liver recovers.
Re Milton Keynes. There is at least one member of this forum who lives near to MK. I am sure if he notices your post he will contact you.
Good luck and don't worry too much. It is early days as yet but at least you have found this forum and believe me you are not alone.
If you have any further questions do not hesitate to ask here.
Sandy