Families may not be as numerous as before, but there is always someone around who will have a kid the same or similiar age as your kids! Depending on where you go to vacation, I wouldn't think you'd have any trouble for your kids to find some playmates. Something you should take into consideration, at least for your summer trips, is maybe visiting close to somewhere where the kids have cousins, or one of your friends is bound to have a reative with kids close to the age of your own children. I'm a half and half too and my parents started by sending me to my aunts house, and there were kids close to my age in the neighbourhood, and as I got older, I went to summer with a cousin and her family, again, she had a group of friends and finally for the past 9 years, I went to the beach with a friend of my family with their kids (both my age) and we always had a group of friends to hang out with and practicing was no problem! Good luck and have a good trip!