Glad to report that I'm up and running.
Here's what I did (basically I followed directions):
1- download and run the media creation tool:
https://www.microsoft.com/en-us/software-download/windows11
2- select option to Create installation media for another PC;
3- select option to Save an ISO file to your PC
4- once ISO downloaded, just drag it to an ntfs formatted flash drive
I used nirsoft ProduKey to get the windows 10 product key from my Parallels win10 VM
5- Because I have an intel processor, I followed these instructions:
https://kb.parallels.com/en/128449
6- don't skip the customize settings step to install TPM
7- it didn't take very long (<30 hour)
8- I still need to reinstall my windows programs in the new VM, but at least Win 11 is working in Parallels now. My documents and files are stored in one drive so I can delete the win 10 VM once I've run the new VM for a couple of days.
For what it's worth, here's what I did yesterday and earlier today, both of which generated the unsupported processor error even though my processor is on the list:
I used the option to "Download Windows 11 Disk Image (ISO)". Note, this IOS image was larger than the ISO downloaded using the media creation tool.
I Used Rufus to create a book disk and installer.
Plugged the flash drive in my Mac, mounted it in parallels, Ran setup.exe from within the win10 VM.
When that failed, I tried to create a new win11 VM using the direct download ISO image (vs the media creation version), which also failed due to the processor message.
Note that "check for updates" in win10 only showed a message to get ready for windows 11 or similar, it never showed an available update to win10.
YMMV, good luck, Mark