You should be determining whether to shoot a particular deer or not with binoculars, not the scope. If low light is the limiting factor then you need to optimize the exit pupil and select either an illuminated reticle or heavy post/plex reticle. High magnification in a scope usually doesn't correlate well with low light performance, so a fixed or variable that would go down to 2/3x should perform better than a fixed 6x or 8x. Trying to manage two scopes is going to cause more problems than it is going to solve.
