I just helped a friend migrate from a 2012 Mac Mini to a new Studio.
It actually went well, with a few provisos.
First:
Do you keep any user-created folders (folders that YOU created) at "the root level" of the drive now? (Root level is "the first level you see" when you open the drive icon).
If so, that's no longer permitted with the new CPU/OS.
You need to re-locate these folders into your home folder somewhere.
If you don't, they will be located -automatically- during the migration (and probably end up in the "users/shared" folder).
Do this before you attempt the migration.
Second:
The best chance of success will be if you use an EXTERNAL USB drive.
If you already keep a backup on an external drive, you can use that.
If you don't have a backup, I suggest that you create a CLONED backup using either CarbonCopyCloner or SuperDuper.
Both of these are FREE to download and use for 30 days ... doing it my way will cost you nothing.
Third:
When the Studio comes, take it out of the box, set it up, but DO NOT PRESS THE POWER ON BUTTON until your backup is connected and ready-to-go.
You probably DO NOT want to create "a new account", but rather keep using your existing account (is that a correct assumption?).
If you create a new account and then use "migration assistant" to bring over your "existing" accounts, you'll end up with TWO accounts (representing "you") and permissions problems if you try to move files between them.
Fourth:
You may do better by NOT migrating applications at all.
REASON WHY:
Many of the 3rd-party apps you're using may need updating or won't run at all.
I suggested to my friend that he try his apps "from an external drive" one-at-a-time, to see if they ran, and could move them "manually" (between applications folders) if they did. If they did not, then don't copy them over at all.
NOTE: As you will have migrated "everything else", the settings, etc., will already be "in place" for such testing.
Fifth:
NOW it's time to press the power on button and begin setup.
Start "clicking through" the setup procedure.
When setup assistant asks if you wish to migrate, YES, you do.
"Aim" setup assistant at your backup and give it time to "digest" everything (may take a while).
Setup assistant will now present you with "a list" of stuff that can be migrated.
I suggest you UNCHECK "applications", but migrate everything else.
It will take a little time for the migration to go through.
When done, you should see your login screen, just as before.
So... log in and start looking around.
Do things look ok?
At this point, because you created a CLONED backup, you can start browsing through the 3rd party applications on the backup, to see if they run or not.
If they do, just copy them (again, I recommend testing one-at-a-time) to the applications folder on the Studio, and then open them again, to be sure.
This worked for my friend and I predict it will work for you.
Good luck!
Please save this thread, and come back and tell us how it went.