Tom, not sure if you know this or not but I have a 20 year old daughter who I never lived in the same house with until she was 18 and a half years old. Actually, I only lived in the same state as her for 2 years of her life up until that point.
You do what you can, you communicate with them as much as possible and whatever way you can. I would have my daughter for spring break, 1/2 of xmas break, and 3 weeks in the summer. I took advantage of what little time we did have together and when she graduated high school she chose to come live where I am.
The important thing for them to know is that you love them, you want to be with them, and that you are doing all that you can for them with what tools you have available.
I doubted how strong my R was with my D for many years, only to find out that I did exactly what I needed to do even though I didnt trust it myself.
