Few side notes:

I replicated SSID and WPA key. Transition was seamless.

I powered down the older wireless network. As I powered the new one back up, my current 26 "IoT" devices were just immediately on line.

I now have one single SSID for both the 2.4GHz and the 5GHz wireless networks, and it is working nicely so far. All devices capable of 5GHz are on 5GHz.