Transfer Cloudflare domain - downtime and payment

I am working to change my hosting account as I do not know the email associated with my original account and reset emails aren’t coming to anyone at my domain. I can update my nameservers with my registrar no problem and am prepared to do so.
I am wondering:

  1. will my site experience downtime with the migration, and
  2. if my other, lost Cloudflare account is on a paid plan, how it works transferring to my currently free plan. Will I have a grace period where I can pay the appropriate amount?
    I have followed this so far
    Move a domain between Cloudflare accounts · Cloudflare Fundamentals docs

Can you create an Account ticket and share your ticket number here? You can open an Account ticket here, Use the account you are using here, reference the email for the other account and the associated email.