@rachie28
For everyone saying she is being unreasonable, you haven't lived it! I have and they only went for 6months! The nightly question on where Nannie and grandad were and when they would be home was sometime heartbreaking. My daughter did get used to it and the question stopped, but it was hard for a few months. If ur child see them more then 4 times per week think about reducing it as this was our problem, going from 4 to nothing was heartbreaking for my child, and I will be doing it differently next time.
This ^
@mrsbitaly
Wow some people are horrid. They asked for advice not to be made to feel like crap. They were quite obviously not wanting their child to be upset with the move.
And this.
In typical mumsnet fashion, the OP has been jumped on and torn apart. She only asked a bloody question. Unsurprisingly she hasn't been back. No wonder, with all the vitriol that's been spewed on here.. 
@Hard2Find (if you're still reading,) is it your grandparents you're referring to, or your DC's grandparents? (So, your parents.....)
I don't think you need to reduce contact though, as your DC is only 7 months old, and will only know their grandparents as 'distant' anyway.
I have never, and WILL never understand why people move multiple 1000s of miles (overseas,) away from close-kin family. What are they trying to get away from?
There are plenty of opportunities in this country, that you can access without going across the world!
If you ARE pissed off and angry (if it is your parents, and they are leaving,) then YANBU... I mean, they have every right to of course, as it's their life. But I don't think you can care much about your family if you swan off to the another country (across the world,) to live permanently.