Point an external domain name to a AWS Route 53 subdomain

I am building a website builder. https://savvy.site. A customer builds their site and is allocated a subdomain. For example: mistertee.savvy.site Where mistertee is the subdomain and savvy.site is the domain. The site is then hosted as a static site on S3 using cloudfront and SSL cert.

I'm busy investigating how I can support the following: the customer already owns a domain registered with some external domain registration entity (for example xneelo or godaddy) and the customer would like their domain to point to subdomain they created on Savvy. In my example they have registered mistertee.com (in the past) and would like to point it to mistertee.savvy.site

Option A:

1. Add a redirect (CNAME record) in the external registry to point to the mistertee.savvy.site's cloudfront entry for eg abcdefghij.cloudfront.net
2. Add a new origin in cloudfront mistertee.com But this requires an SSL cert.

Option B:

1. Create a new Hosted zone for every site that will be pointing to a savvy.site. In my example: mistertee.com
2. In this new Hosted zone add a redirect to mistertee.savvy.site (A or CNAME?)
3. On the external registrar how do I point to this Hosted zone. I discussed with xneelo support and they suggested I get an IP address which I set to the apex record in their DNS config. They suggest NOT transferring all the NS records because then I'd have to manage mail records too on Route 53

Am I on the correct track?