I don't understand how most people's UIs breakdown after new patches. As long as you keep your mods up to date (WoWMatrix makes this task a joke) and use popular/community approved mods you should have a very few problems.
All good mod coders will test their mods on PTR before every patch and make the appropriate changes to ensure a smooth transition to the next patch. Only big changes by Blizz to the background code will cause delays in mods being ready.
One piece of advice: try not to use pre-built UIs, those are the ones that break the most after patches especially if the author doesn't keep it up to date properly. Rather start off with one, remove addons you don't need and then keep that up to date on your own via WoWMatrix. Will prevent many major headaches.