It's always best to see what the impact will be on your traffic, since TLS support varies among different countries, different types of businesses, between mobile and desktop clients, and various other populations.
You can log the TLS versions and cipher suites used in Apache httpd and nginx. Once you've done that, wait a week (or however long you feel is necessary to get an accurate representation of your site's traffic) and then you can build a report of the requests using the configurations you want to disable.
It's important to remember that just because a client used a particular cipher suite, that doesn't mean they have to - they may fall down to another supported cipher suite if that one's no longer allowed. If you want to try to figure this out, pull out the user agents that are using the endangered cipher suite, use a tool to reverse the client name out of the user agent, and then you can test using that client (assuming it's a well-known one) to see what happens in your testing environment.