We took the leap ten years ago and left long time friends and some family to move to Palo Alto, CA from years in Phoenix, AZ. Yes, we have missed our friends but have managed that by going back to Phoenix to visit about three times a year. We also kept an apartment in Phoenix for about two years and would spend a number of weeks in the spring visiting friends and places we loved.
What made the difference for us? We were invited by not just two of our daughters, but also their husbands to move close by. It is important to remember that in-laws sometimes need their own space and growing families are very busy. It has taken us some years to develop a new set of friends and we had to actively involve ourselves to do that. Most people already are busy with friends they have had for years. We found church, the YMCA, adult classes and inviting new friends to our house were helpful techniques. We are active, busy people and spent a lot of energy seeking out new friends and activities like a book club, singing group, and a genealogy class.
If you like adventure and new things and view the move as a new and exciting experience no matter how it goes with family, it can not only work out but be very rewarding. Our children were great to include us and introduce us to the area and to people we might enjoy. However, they invited us here because they wanted to share their lives with us. Also, we actively worked at not being overly dependent on them.
We love our new setting and being near some of our children and grandchildren has been a real delight and blessing, but it took work on our part.
Good luck how ever you decide.
ElderChicks 
I agree…the payoff of being near family and watching grandchildren grow is worth it. We also found volunteering to usher at music and theater events a great way to meet people with similar interests.
Thanks for the tips on making a successful later-in-life move. I’m looking forward to ours and have a strong feeling our move will be rewarding as well.