All I do is live in the wasteland, in a city (eventually), and from a base defense point it's not nearly as hard as you are describing. I'll have to see what my player level is but I'm sure it isn't very high, and I'm on day 27 or so, single player insane mode. Most nights I have very few zombies coming by, it's pretty quiet. There's a strategy to it though, when a random horde comes by just sit tight and be quiet. You know, as if you were in a real zombie apocalypse. My base defenses for the first 3 horde nights were stone arrows and wood spikes, with some iron spikes thrown in as I could make them. My horde base is a garage next to a house. The house roof has all my supplies. And I killed them all, I didn't have to resort to surviving until 4am hit.
There are tricks to it though, ways to survive. And I'm real hesitant to post them here because I feel like I will be punished for coming up with ways to survive in the wasteland by the developers. Not cheesy ways, or exploits. Just using my brain like anyone else. You know, like posting how to wrench land mines, or shoot them with arrows. Now in 20 that doesn't work anymore.