I miscalculated and dry brined my 12 lb. turkey with 3.5 tablespoons of salt instead of the recommended 2.5 (using the 1 tablespoon per 5 lb. method).
It still has another 12-16 hours of brining ahead, should I remove it and rinse or let it ride?
Not at all, it might be extra good! :) What kind of salt did you use? An extra tablespoon of kosher salt (particularly if it's Diamond Crystal, which is less salty than Morton's kosher) spread across the whole bird shouldn't make a huge difference. If it's one of the saltier brands, it still should be okay, and hey, you can just make an effort to have less salty gravy (be judicious in using the drippings, as they might be salty, and definitely use an unsalted stock).
You will be fine. When i started brining all the recipes recommended only a few hours. I started experimenting with longer and more ingredients and it was all the better. Now the recipes all seem to be longer and stronger! The first time I did it we did a side by side test with a traditional method and brined and it has been brined every year since. Enjoy!!!
I forgot to say that it seems like so much salt but diluted it really isn't and the chemistry works.