How best to keep my localhost on Http while my Remote production is on Https

The correct approach is to use HTTPS everywhere, and to migrate to SSL properly:

  • remove the Really Simple SSL plugin
  • change your sites URL option to the https version
  • search replace your database so all content uses the https URL via WP CLI or a search replace tool ( do not use an SQL query it will break things )
  • update any hardcoded strings in your theme from http to https

Then finally:

  • set up a local SSL certificate and trust it in your browser

A lot of local dev environments will generate the certificate automatically, e.g. VVV or Local.

The alternative is a painful manual search replace each and every time you pull changes down, and push changes up.