Trying to think of negatives for you....
It is a tie- not just for going away for overnight stays, but as with any animal, you can't be sick and not go out and milk, it all has to be done regardless.
Some people will tell you routine and times are really important (I know people who religiously milk at 6am and 6pm), but in reality, your goats have to fit in with your routine whatever that might be. I know people who milk at 11am and midnight, in order to fit the goats in round working shifts.
Ours know to be flexible, they normally get done at about 8am and 8pm, but that can vary according to what we are up to, and also shows as we have to milk at different times at shows. If there aren't people in the goatshed by 5 past 8, they don't mind at all!
It will just generally increase your workload, there will be extra feet to trim, milking takes a little bit of time, straining the milk, feeding them morning and night etc etc. Also, it's more common for dairy goats to kept inside more, so there may be more mucking out! All small stuff, but it will increase the number of things you have to do.
You probably are best to visit a few people before you commit, and try and decide what breed you want. GG's are an endangered breed, and will probably do everything you want, but think about it. *Ahem* Don't Anke let hear this but GG's aren't my favourite breed* don't really know why either.
I have to say I would probably recommend BT's, they milk well, will run through (milk on) for 2 years (or longer) and are nice and hardy. Pure toggenburgs are lovely too, but a little harder to get in Scotland.
Beth