I've done a similar thing just a couple of weeks back. I've held onto my 13 mini since summer 2022 and, honestly, it has been a perfect device. Its form and size is still the best out there. However, its age was starting to show and even though my battery was also at 80%, I decided not to wait for it to drop to 79% to change it with Apple (the phone was still on Apple care). It took me some time to get used to the 17, but the positives outweigh anything else. It's just a great phone and does feel like it's a proper upgrade from 13 series - something I did not find with previous models. Seeing that Apple is not going back to smaller models, I think upgrading to 17 (not Air, it's too big and uncomfortable, it just feels weird) is the best option on the market now for iPhone users, particularly those with 13 mini. I kept my mini just for personal archive. It's a great phone and I am not planning to part with it, just won't use it as my main device anymore.
PS the guy at the Apple Store in Paris told me he knows and sees a lot of minis either being upgraded to 17 or people just bringing back the bigger phones they bought to go back to using the mini, including his own brother who refuses to let go of it.
PS the guy at the Apple Store in Paris told me he knows and sees a lot of minis either being upgraded to 17 or people just bringing back the bigger phones they bought to go back to using the mini, including his own brother who refuses to let go of it.