Krooz,my suggestion is, stay with the red-dot. If you can shot it well at 75 yards. The reason I say that is, a red-dot will get you on target quicker than a scope. Shooting off hand with a red-dot is a lot easier than shooting off hand with a scope. The light gathering abilities of the scope has no advantage in low light conditions, with handgun scopes.
The scope has an advantage if you have a rest, and good light. In low light conditions the reticle is hard to see on dark colored animals. I have had to pass on a few animals because, I could not see my reticle in the low light, had I had a red-dot the shot would of been made.
If you decide to go with a scope get one with a big objective. It will help some, but a handgun scope does not gather much light as some think they will. Either a Leupold 2.5X8 or a Bushnell 2X6.
I currently own 4 handguns that wear Ultra-dot red-dots and 1 that wears a Eotech holo sight. They work great in low light conditions.
I also have 5 handguns with handgun scopes, a 2 X Leupold, a 4 X Burris, a Bushnell trophy 2X6, a Bushnell Elite 2X6 and a Leupold 2.5X8.
I use my gun and scope/red-dot combination to the conditions I will be in. If I am sitting on an open field and I get the most of the light, I go with a scoped handgun, If I am in the woods where the light fades quickly, I take a handgun with a red-dot. If I am going a spot and stalk, a red-dot or open sight handgun is what I go with.
With open sighted handgun, low light will get you out of the woods faster than if you had a red-dot.
Good luck in your choice.