Is it possible to modify failure conditions for already started scenario?

We are playing custom scenario made by someone else in multiplayer hot-seat mode. After investing significant time into this game we found out that it has some weird failure conditions. Our save file is right before the game over for one of the players: player-1 ends his turn, player-2 loses.

Is is possible to modify this scenario vie editor to disable this custom failure condition? Or may be we can do something with our save file? Or some cheats exist? Any solution will work, we just want to continue this game like it has traditional "lose all towns and heroes" losing condition.