BTW, I believe it should be MUCH CHEAPER to do live action filming, than 3D modelling, for certain cutscenes.
There are lots of cosplayers who would be happy to sit around a round table and discuss strategy with H7 Ivan, for instance. You could get actual fan volunteers to do all the work, and just pay the cameraman and maybe loan a few rooms in some castle, and get good enough life-action quality.
Understandably, certain actions like flying dragons and huge armies won't be possible given budgetary constraints. But that's not beyond a good scriptwriter to finesse. Sometimes you can just pay a studio a bit of money to reuse a few seconds of their discarded footage eg a brief clip of some flying dragon that didn't make the final cut in Game of Thrones. That is better than having static 'animations' without moving mouths like in H7.