Apache Dynamic Routing

I think this crosses several Apache boundaries (and networking too). I am looking for a little assistance understanding what may be involved.

I host (at home) a small CMS system used by around a dozen people. I cannot always contact them when an outage is required or just happens. I'd like to have a redirected site show a 'down for maintenance' page when I can schedule down time. I'd also like to have the opportunity to point them to a different host so the interruption may not be experienced at all. I have a development web host that is internal and not accessible to the internet but at times I'd like to test updates externally.

Again, I host this at home. I have a non-static IP internet connection that I have defined a dynamic DNS host (ie mysite.ddns.net). I have a registered domain that I point back at the dynamic host (we'll call it registered.net). At the firewall/router, I port forward 80 & 443 to the internal host. On the internal host, all port 80 traffic is then redirected to 443 and all virtualhosts/sites in Apache are 'named'. Let's say the landing point is cms.registered.net. I also have letsencrypt certs installed for all sites. This has worked well for years. Hopefully this diagram helps.

|
traffic ======firewall/router======host 1
| <cms.registered.net>
| <beta.registered.net>

Since I port forward from the firewall/router to one internal host, I was thinking that I might be able to use that host as an 'Apache router' to further point to other internal hosts serving websites by name.

The problem that continues to allude me are the SSL certs and how I would implement mod_rewrite and mod_proxy(?) to keep the flow. Here would be an adjusted diagram.

| host 1 (cms.registered.net)
| /
traffic ======firewall/router=====apache-rtr-host ---- host n
| \
| host 2 (beta.registered.net)


I appreciate any feedback/thoughts you might have. Thanks.

 

Well I spent a lot of time formatting how the diagrams looked but for whatever reason they aren't showing correctly. I also can't edit my post?! Hopefully the description is enough.