When we did our 3-mo trip, DW was homesick for GK's by the time we hit Memphis. I advised her to use her cell phone and call them everyday if necessary, but we were not going to turn back before getting lobstas in Maine.
That did the trick, barely.
Nowdays they have Skype, etc so she can communicate with GK's, face to face. That should make it much easier.
Our youngest, 13, 5, and 3 we see once to four time a week. So, if we don't see them weekly, we go thru withdrawals.
A month ago I found out I had late stage cirrhosis of the liver. Makes me very happy that we did our long trip shortly after our retirement in 2007. We didn't want to wait, in case one of us got sick, in a bad accident, etc.
We take taking full advantage of kids and GK's. They come over very frequently to swim and just gab.