A few months ago, I did a Migration from 0365 From GoDaddy to a Standalone O365 tenant and I had some issues.
First, you won't be able to register your domain with the new tenant. You will receive an error message telling you that the domain is already registered in a tenant.
To Goddy remove the relationship, they will delete your account. So you already had your backup.
In my case, I couldn't backup the emails because in GoDaddy I didn't have a role to extract the PSTs, so I did a manual backup of the email.
I had to create the user manually in the new tenant.
Sorry for not bringing good news about my experiences.
I recommend you validate the pain points that I shared with you.
Hope this helps!
Remember to accept the answer if it is helpful.