Here's an example of 45 20megapixel photos stitched together.
ca: 88x40in @ 300ppi
ca: 132x60 @ 200ppi
ca: 260x120 @ 100ppi (~21x10 feet!)
It's possible to stitch without distortion like that shown in my example. Also, FYI the camera is a tiny mirrorless camera (sony a5100) that was modified by removing the infra-red filter that covers the sensor.
It's hard to wrap your head around the process. Typically, you will be using a moderate telephoto lens for the process and can make a super-wide angle final pano. In this case, the lens was a 50mm on APS-c (75mm equivalent).