So only 1 recent save?
How much reaction time do you have after loading the game? If you are playing on PC and email your save to support (supportdos@larian.com), I might be able to teleport a character away from the blast radius, with enough time to hit a hotkey.
In Windows, each save is a folder in the '..\Documents\Larian Studios\Divinity Original Sin Enhanced Edition\PlayerProfiles\<ProfileName>\Savegames_patch' folder.
OSX is similar and in Linux they are in the home directory.