How do I set a fqdn which exceeds 65 characters?

I have the requirement for an FQDN which exceeds 65 characters. What's the easiest way to go about this on centos 7?

I've been provided with a root domain name which is roughly 30 characters and my hostnames are typically 40-50. Usually this wouldn't be a problem as the root domains are < 10 characters, but very suddenly it's likely to cause a problem for me.

My first immediate thought was that the FQDN does not include the domain name, but I can't see where this is set and even when I think I have set it right, the fqdn is stripped at 65 characters (does the FQDN include the domain in the character limit?). Furthermore I'm also curious if this is remotely possible without compiling my own kernel which is a last resort.

For example purposes, lets say the domain name I've been provided is: areallongexample.com and my hostname is usually: a.long.hostname.with.lots.of.required.fields.

This is straight from my system: