Adventures in comfort baking

This apocoronalypse is getting serious. There's no plain flour to be had in the market, even for ready money!

Wellinghall went out foraging last week, and came back with a packet of rye flour, and another of Ancient Egyptian ancestral wheat flour. I also have bread flour, white cornmeal and Ancient Orcadian ancestral barley flour. Oh, and I can grind nuts for nut flour, I've been using that to pad out the plain flour for pastry, and made a lovely chocolate and chestnut fridge cake last week.

Fortunately I'm a reasonably confident baker with a reasonably well-stocked cupboard. But the plain flour we've got is now low enough that I'm beginning to hesitate over my usual trick with an unfamiliar flour of mixing it half-and-half with plain or bread (according to what I'm making) and am about to level up to attempting things like pure beremeal or cornmeal baking. This could get interesting!

Anyone out there got more experience than me with alternative-flour baking? Any tips? Can I use bread flour for pastry?