We thought we would like to go away for several months at a time after retirement, but in reality (for us anyway), we missed our home, family and friends and our gym membership! Unfortunately no grandchildren. It all sounds good on paper but when you are away for long periods of time, you can't go out every day/night and can get bored too! (although when I was working I wouldn't have believed that!).
We find 2 to 3 weeks is more than enough and we're ready to come home. After a couple of week's I'm itching to go away again! However I feel sure if we had grandchildren to spoil, that wouldn't be the case.
Obviously we're all different as we know people who go away for two months at a time travelling and they love it! However nice the accommodation is, that we stay in, after a while I want my own things at home.
If you didn't give it a try at least once, you will never know and will always wonder. Try a month first, even if you decide these trips away are for you - a month isn't too bad not seeing the family.