Not something I would do, especially with tile and other labor-intensive and permanent finishes.
My choice was not to delete windows. Consequently, I needed to account for access and things like condensation. My solution was to build my interior standing free from the exterior wall (secured at points in the ceiling). It's a half wall with a clear shower curtain. That gives me air circulation, and more importantly, access to the window to monitor for condensation and leaks.