How to upgrade ATT HTC ONE M7 without losing root

Hello all, I have an AT&T HTC ONE M7 that is currently running Android 4.4.2 with HTC Sense 6.0 (software # 5.03.651.3). I have rooted it with TWRP and SuperSU and need some guidance to update my phone without losing the root (or unroot/upgrade/re-root). Can't seem to find anything. I want to stick with the factory ROM ideally, but would be happy to take a look at any other that is comparable. Not looking for added capability, just want to get my phone up to date.

Thanks in advance!!

Signaldog