I did this briefly when I left NZ, silly really and more just being too young to be honest enough to end it ad selfishly hedging my bets.
Anyways it has always struck me as the worst of both worlds, among the good things about a relationship is having somebody there to keep you company and support you. When you are single you can do what you what, with who you want etc.
If you are in long distance you don’t get the company and support, and you don’t have the freedom to compensate for it.
(just my cynical view – if you are happy go for it !)