If you wait for anything, wait to see what the S 11 brings to the table, that will give you a good idea what to expect. As some has said, the camera will probably be the main improvement, and if that's the case I would do it now. A lot of the new stuff now days are just what I call gimmicks, like 3D scanning, neat, but how often the majority users going to actual use it, you play with it once and the WOW effect is over, and Samsung pushed that feature hard in the release presentation.
Guess what I'm saying, you will always be wondering if you should wait for the next version. The updates are getting to be more and more just minor tweaks.
I say pull the trigger and get the note 10 version you want. If you get to the note 11 and it's all that and a huge improvement, which I'll be surprised, then get the note 11. Samsung usually does a pretty good trade in, last year you could get up to $600 to trade in, so it could be a $300 difference to get both. My suggestion, keep your note 5, that may be on the list that you can trade in. On the note 10, we were able to trade in the note 4 for that. I traded the S5 for $450 thru Verizon. They usually have good trade in programs on new releases.
I for one am kind of jealous of you. You're going to be coming from the note 5 to the note 10. That's going to be a huge improvement, it's going to blow your mind the differences, it's not going to be a baby step improvement, and you got to skip the note 9, which wasn't a bad phone, but to me it wasn't great, specially the display. I was disappointed in it myself, glad I got rid of it. I can't say that about the note 10 or S10, the display is amazing.
Reward yourself for sticking with the note 5 all this time, you've earned it.