Someone fell over drunk walking home from the pub late at night late last autumn. It wasn't even that cold. They were discovered about 6 am, at which point they were in very serious trouble indeed with hypothermia or whatever. This was about 50 metres from my front door in central Manchester – a lot of people live here and walk around at night. We even still have milkmen. And the guy wasn't riding a bike.
OP is making the point he rides somewhere where it is less likely to be discovered than the centre of Manchester, recognising there is a risk he might fall off and be without help, and asking what people do to mitigate the risk if anything.
I used to be far more sensible about this, but over the years have become less so – my wife will just know I'm off somewhere in the peak district or whatever usually. I carry pretty much exactly the same stuff with me as on a group ride, but then we all carry stuff to be self sufficient anyway. I ride with more caution and take less risks when alone, but I'm also more prone to explore daft places that may or may not make a good ride for mates later.
Ta to the OP for the reminder – I should make an effort to be more specific about where I am and what time to expect me back in future.