Serge Ramelli has a new video that illustrates how to manually blend multiple images in Photoshop. The photos he's using aren't real estate type photos but don't pay any attention to that. Look at his technique and workflow that he's using.
This technique (multi-image blending) is used by some real estate photographers extensively to deal with window issues, light areas independently, replace skies and to just deal with problems in general. But be careful, this can suck up a lot of time!
The interesting variation that Serge adds to the workflow in this tutorial is starting with the two layers you are going to blend in Lightroom, making adjustments in Lightroom (because most adjustments are just easier there) before sending the two images to Photoshop as layers.