Ive never done this, but I wish my parents had.
They moved after dad graduated college, saying it was only for a few years, and 30 years later, he is still working (a GREAT job) at the same place. He is honestly much more successful than he probably would ahve been staying near his home, as the opportunities are so much better here.
But my extended family is all 6-10 hours away. If my parents had stayed even in the college town where they met, we would be 2 hrs from one family, and 3 from the other.
Growing up, having the long drives, not really knowing any of them well, I always said I wouldnt do that to my children (and I didnt). We live about 15 minutes from my parents, and 40 minutes from dh's.
But I never realized how my parents decision to live far away would effect MY children as well. DS has been back to each great-grandparents house twice, and to visit other various family members 2 more times (6 long trips in 2 years).
My grandparents are now elderly, and very much miss out on all of my ds's life. It isnt feasible for us to travel more, as we have dh's extended family to see as well, and we dont have a lot of travel money, but my grandparents feel that we are not doing enough to let ds have a relationship with them. I feel horrible for not getting to see them more often.
Anyways, sorry for my rambling, but I just wanted to tell you my story, and that if you stay it will definitely affect your childrens relationship with their grandparents and family now, but will also for years to come.
I hope no one is offended that chooses to live away from family, as I dont mean to say that everyone thinks like me, but for us it has really been hard to be all split up.
However, you have to look at your financial future and your ability to raise your children in the new area. Those are questions only you can answer.