So sorry to learn how you feel.
It is so difficult when our children move away. My son told me he was going up to Manchester area. I can remember so well, the when he told me, we were sitting in his garden in his (and DiL's) house less than five miles from mine. BBC were moving his department and he was seriously considering going with them. I excused myself and went to their bathroom, looking into the mirror there, I gave myself a talking to - they must do what is best for them, not me. Moving would mean better job prospects, much better house, etc.etc. Managed to go back downstairs and smilingly wished them Good Luck. This was five years back, still miss them, but also enjoy my long weekends that I go up and spend with them. The decision was totally right for them and I am glad they made it. Think it was harder for my DiL who loved her job in London and had to give up a final salary pension scheme. So glad she has settled into a new job, and really loves the beautiful house in such lovely surroundings in Warrington which they were able to purchase.
My youngest daughter (20 plus years ago), very suddenly threw up her Phd course and went out to Northern Ireland. Her flat mates brother had come to visit and they had 'fallen in love'!!! Took a lot to come to terms with all of that. Happened in less than a week.
Eventually, she re-trained as a Ed. Psychologist, they married and then had two lovely little girls. I managed to visit on several occasions, but was delighted when this year the whole family moved back to England (South Coast). Can now really get to know those two g.daughters more.
Each generation must do what they consider best for them and their families, but nothing is absolute and the main thing is to always remain on good terms with them.
Do go to visit them asap, get to know their currently adopted home and country.
Who knows what can happen in the future