The distance will make it a bit easier for you when their time comes. I saw my folks about every week until my dad died when I was 27. My mom had no one but me after that (I was an only child), so I bought a house near the family homestead knowing that in the years to come mom would need more and more of my help. I visited her nearly every week. A lot of people don't think about it until it is too late but most people never regret spending more time with their aging folks and creating new cherished memories, getting to know them better as an adult, revisiting stories, pictures, people and places only you and they know from your youth. Often these conversations reveal nuance that you may have missed or misunderstood as a youth. Once they are gone, you wont be able to enjoy memory lane and good times with them ever again. Like a part of you has died with them. Having your own family that depends on you, a job/career, friends and hobbies will help you to almost forget the void they left as life must go on for the living.