Kristy - oh, how I can understand your concern!! I've been through this so many times in the past mainly with our 4 previous dogs when every year, Paul and myself used to travel to Australia and various other countries for 6 wks every time. We were fortunate as my son was living at home then. Now, I won't pretend that you are not going to worry and miss little Stewie like crazy, no matter who is looking after him but forget you..?!! NO WAY!!
Ours used to look a bit confused when we got back maybe but it just took all of 1 second for them to run to us yelling their heads off!
It's important to really go into detail with whoever is minding them re his housetraining so that his little routine doesn't vary much from yours and you shouldn't have much of a problem at all. Have a truly wonderful time and I was going to say "don't worry" but I won't bother saying that lol!! Ana xx
ps I always left an item of my clothing for them and it is often a comfort to them if you do that.