It would be out of the question for me to trade my car straight up for a new C8 Z06, whether you think that is a reasonable trade in the current market is up to you and I wish you luck finding a C7 ZR1 owner that will do that trade when you get your C8 Z06.
I have a 1 of 1 ZR1 in Canada and I went through a lot of "stuff (I'll just say that)" to get it considering I was late to the game in finding my car and buying it back in July of 2019. A "regular" C7 ZR1 I believe did MSRP in the CAN$140k range, most if you add the "desirable" options stickered at around CAN$164k area (what mine was) or higher with SODP and all the other options ticked off. It's easy to check BAT or anywhere else to see what they are listing and selling for, especially if they have all the options and M7.
A 5 mile low wing, base seat 3ZR A8 car was listed by a seller for US$189k and it sold for US$185k last week and a bit, do the exchange and you can get an idea what a full load M7 similar car would sell for (much higher than that price).
Yeah I understand time and tech marches on and for sure a C8 ZR1 or Zora will be better but mostly it will be better because of electric hybrid (if they are going that route) assist or whatever they are going to call it. I'll stay with my old fashioned gasoline powered propulsion that is the essence of what Corvette is to me.
My car is posted in the C7 ZR1 section, pics are there and videos also, haven't tracked it yet but I have plans to when I'm ready.