Debbie, those girls are adorable! I'm in the same boat as you, my three grandsons live in Austin Texas, and I am in Ontario, Canada, not too far from Toronto. I fly down to see them 3-4 times a year, so I don't know how many miles it actually is. However, this year, after I retire, I hope to drive it once and stay down there longer than the one week, which has been my custom.
Also, this year, I am going to get a Canadian grandson (beginning of May) and for the first 10 months of his life, he will be living about 10 miles away from me. After that, he'll be going back to Ottawa, which is a 5 hour drive.