Two thoughts for your endeavor:
1. It does seem likely that the 11 will be discontinued when the 14 is announced, so if you're tempted by the 11 (and want it new from Apple), you might want to order it now before the announcement. If you buy it in store, you'll have 14 days to return; if you order it online and have it delivered, you essentially have a 28-day de facto return period. You could get it, try it, and see. You could also get it, keep it unopened while you're debating, and still return.
2. You mention using an 8, and I wonder if you've used an OLED iPhone. I love my Apple tech, but in the past few years I have had horrible issues with OLED. (I am one of the small minority who has a physically bad reaction to Apple's OLED with headaches, nausea, dizziness, and general discomfort because of PWM, dithering, etc.) You may not; you may get an OLED and absolutely love it. Just mentioning this as something to consider. Fortunately, if you did have a bad experience with OLED and the 11 was gone, you could always get an SE.
Hope you find a phone that works well for you.