@apolloparker907 – Your plan sounds solid. My house is late-70s ranch and I did just what you’re describing. I kept the general layout of windows the same (didn’t move openings around, except I turned one small bathroom window horizontal for privacy). I chose an almond/tan frame color instead of white, which goes nicely with my brown brick. And I skipped grids entirely for a cleaner look, since the original windows had none.
The result: the house still looks like its original self, just refreshed. Neighbors said it looked 'cleaner' and more 'updated' but couldn’t even pinpoint why at first until I told them about the windows. That’s how you know it blends well – it doesn’t scream “I’m a new addition,” it just looks right.
One thing I did add for a bit of modern flair: in our foyer, we had a narrow floor-to-ceiling sidelight window next to the door. I replaced it with fluted privacy glass (no grids, just a textured glass). It glows nicely and adds a modern touch but since it’s just one element, it doesn’t throw off the whole style. So you can do a small creative thing here or there like that.
So yeah, go for the small tweaks (color, maybe slightly larger sizes if you can without big construction, minimal grids). It’ll likely give you that subtle modernized look without losing the character of your 80s ranch. Good luck!