My room is also a bit over 12' wide. My eyeballs are 11' back and I am very comfortable with a 120" 16x9 screen.
When I set up my theater, I projected onto a bare wall for about a month before committing to a screen. That allowed me to play with sizes from 90" to 135" and to see what worked. I finally settled on 120" My kids wanted me to go bigger, but it was killing the space I needed for my main towers. I feel the speakers are too close to the wall for ideal sound right now, but life is a compromise. If I ever make a change, I would go for the 4k acoustic transparent fabric and place the speakers behind the screen. That is something you should consider anyway for a retractable screen. Spend a bit less on the projector and a bit more on the screen.
One last thought on size. 80" may seem big to you right now, but it will be too small in a month or two. You want to get to that point where you feel it is just right for the long haul. In my mind that is the point where the screen width fills to the edges of your vision from your seating position. That is 120" at 11' for me. Anything smaller would just be a big TV instead of a theater.
When I set up my theater, I projected onto a bare wall for about a month before committing to a screen. That allowed me to play with sizes from 90" to 135" and to see what worked. I finally settled on 120" My kids wanted me to go bigger, but it was killing the space I needed for my main towers. I feel the speakers are too close to the wall for ideal sound right now, but life is a compromise. If I ever make a change, I would go for the 4k acoustic transparent fabric and place the speakers behind the screen. That is something you should consider anyway for a retractable screen. Spend a bit less on the projector and a bit more on the screen.
One last thought on size. 80" may seem big to you right now, but it will be too small in a month or two. You want to get to that point where you feel it is just right for the long haul. In my mind that is the point where the screen width fills to the edges of your vision from your seating position. That is 120" at 11' for me. Anything smaller would just be a big TV instead of a theater.