look, rangefinder shooters make distance/aperture/composition calculations in their head nearly all the time. to get the sort of images that i think you're after, you have to become less dependant on what the camera is telling you. take a meter reading of the bright bits and one of the dark bits and the bracket right the way through..... if it's an extreme situation you may have to bracket a half a dozen frames or more. if you have to shoot wide open at slow speeds, use a tripod, a beanbag, tie the camera to a chair and use its timer....whatever.
if it's too dark to focus the camera and there's no DOF latitude, well, i'm afraid you might have to bracket your focusing too. mate, there's no easy way to do what you're asking, you're gonna have to burn a lot of film, experiment with different film speeds, different processing (find yer own grain 'tolerance'.....grin)