The trick to reading HN and Reddit is to not ever visit them on your computer.
Just don’t get into that habit, because if you get hooked it will become a distraction when you’re working.
Instead, just get yourself a tablet. I love browsing HN and Reddit on my iPad in the evenings when I’m not working. There is a great Reddit app called “Alien Blue”, and it makes Reddit great to browse using the tablet. There’s dedicated apps for HN too.
As for subreddits for bootstrappers - agree with some of the other comments. There’s not much on there. HN is great for finding new links and topic, forums like this and JoS are great for discussions. But I don’t see Reddit being a great resource for bootstrappers.
(unless you’re like me, and like to wind down by reading all the nonsense posts