A question for the night drivers here. Sorry it might sound stupid but I really have no clue about night flying.
I'd imagine you can't really see hills or mountains at night unless there's roads or villages, so how do you choose your cruising altitude over high terrain ? I'd imagine it would be something to do with your MSA for the area you're in ?
In the Scottish TMA there's a few bits of high terrain and I don't think the controllers would be able to keep you separated from IFR traffic.
But maybe am just talking rubbish !
Ivor