We have a Roku and an antenna as well. While our antenna is an outdoor one, Doug hooked it up in our attic because it was too close to our electrical lines outside.
Our only issue is that our local Fox station is in one direction and all of the other channels are in another. Since football is on Fox, this is not ok with Doug. He is going to spend a lot of time going up and down the ladder to our attic soon. Keep in mind that our attic has no flooring, only joists, about 50 feet deep of insulation and is about a thousand degrees. Seriously - if we need insulation somewhere, Doug just grabs some from the attic! He is currently researching other ideas to solve the antenna problem.
As far as the Roku, as Erica said, you do not use it to get local channels. We have Netflix, Sling TV and Hulu. We probably use Sling the most as you can watch HGTV and The Food Network on it.
Denise