Replacing windows - cold bridging

[jayc89]

I'm replacing all our windows prior to cracking on with internal wall insulation in all our rooms. The walls are a mix of 220 and 330mm thick and we're going for Rationel FormaPlus, which are 123mm thick, so assuming they sit within the openings by 50mm, leaves between 47 and 157mm internal reveal. 

 

Externally we're leaving the brickwork on show (hence internal wall insulation), I know ideally the windows would sit inside the thermal envelope, but I can't think how we could do that whilst avoiding a thick gap around the windows externally.

 

Do I just suck it up, install the windows as normally and insulate the reveal afterwards, or is there a smarter solution I should be considering?