My entire holding is marshland......
Oh, aye - you'll be above the moorland line? We're just below it, it starts just north of our 'fell'.
(Hereabouts, 'fell' is moorland, marshland is called a 'moss'... it's a different language!)
But yes, since moving up here, initially to a 1000+ acre Northumberland moorland farm and latterly to this Cumbrian hill farm, I have learned a lot about peat bogs, mires, etc. Fascinating stuff and well worth some investigation if you do end up with some such land - I would definitely urge you to do some research, and talk to your local Natural England ecologist, before making any changes which you could regret later.