Redirect IP to domain
Your 2 rewrite conditions clash. They require http_host to be 11.11.11.111 and to be *.mydomain.com, at the same time. Just add an or like so:
RewriteEngine On
RewriteCond %{HTTP_HOST} ^11\.11\.11\.111$ [NC,OR]
RewriteCond %{HTTP_HOST} ^([a-z.]+)?mydomain\.com$ [NC]
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://www.mydomain.com/$1 [R=301,L]
update to willian's answer. you just need to replace the domain name (your-domain.io) from this snippet.
RewriteEngine on
RewriteCond %{HTTP_HOST} ^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$
RewriteRule (.*) https://your-domain.io/$1 [R=301,L]
RewriteEngine on
RewriteCond %{HTTP_HOST} ^111\.111\.111\.111
RewriteRule (.*) http://yoursite.com/$1 [R=301,L]
Alter "111" to your IP