OK guys, I admit on occasion I am too stupid to travel unassisted, so I've come seeking help from the gurus

Trying to sort out Christmas travel and can't face the drive up the A19/A1. So looking at flying since I found out BD serve MME. Unsurprisingly, there is no direct flight MME-EDI, (although there is LBA-EDI as a fall back), but I could connect via LHR (yes, the drive is that bad). But although website will let me book MME-YYC and various other foreign points, it won't let me book MME-EDI - I don't think! Am I missing something?

I could book as two seperate tickets, but then when it all goes horribly wrong through LHR, so far as I know, I'd be stuffed as they'd be on seperate PNRs.....