Grandparent moving abroad leaving grandkids behind

Hi people
I am living in NZ and after a marriage breakdown 6 years ago and due to personal issues I am moving back to Australia to live and retire where most of my family older generation live.
I have 3 grandchildren 2,8,10yrs old (and love very dearly) and one daughter whose children are to 2 different fathers.
I find my relationship with my daughter is not close as she doesn't communicate with me on anything the grandkids do and i find out through Facebook what they have been doing but on speaking terms with her when I do see her . Unless I contact her or she wants something she doesn't contact me or taken concerns on how I am which hurts me very much.
I had recently lost my job and was finding so hard to replace and have felt very alone for past few years missing my home town which I was travelling to once a year.
Now that I have made the decision for returning there . I am going to find it hard to leave the 3 grandchildren and even tell my daughter and the grandkids. I still get on with her first ex and the kids are shared week on week off with one another daughter and ex get on well but I think she gets jealous that he sometimes lets me see the 2 older girls. Where she doesn't let them come to me as much as I would like.
What I am wanting to know is trying to cope with telling them all and then having that contact through Facebook and either Viber , FB Messenger or other means. The older one has always been closer to me with the 8 years getting better and getting closer now.
What I will do is try and commute twice a year to see the grandchildren between Sydney and Auckland.
Does anyone have any good tips or had similar experience.
Appreciate chatting to help me through this transition