For anybody running into a similar problem: most git hosting services set up a subdomain that will allow SSH traffic over port 443, e.g. ssh.github.com, altssh.

For anybody running into a similar problem: most git hosting services set up a subdomain that will allow SSH traffic over port 443, e.g. ssh.github.com, altssh.bitbucket.org, altssh.gitlab.com, etc.