We took in a stray cat about a year ago and moved house to a more rural area soon after.
During the day I leave the back French door open a few inches and he comes and goes as he pleases (our house is rented and no cat flap, we paid an extra pet deposit).
There are a couple of pet cats (they have collars) in our area that seem to be out all night and sometimes if I'm up late then I let our cat stay out late. Recently he hasn't seemed bothered about coming back home though. He just pops in for food and goes straight out again.
When I go to bed I need to shut the door so if he is out when I go to bed then he will have to stay out until morning.
There doesn't seem to be any cat fighting going on here, lots of pet cats but no strays. There also aren't any busy roads nearby but I have seen wild ferrets.
I could leave some food out for him and perhaps put a blanket in the shed and leave that door open. Our shed doesn't have anything valuable in it, we mostly use it for storing rubbish.
Our cat loves to hunt to I suspect that is one reason why he likes night time, he also has a cat friend who seems to be out all night.