Had the DNS issue this morning (75070 zip code) when we got up. Changed the DNS server settings in the Cable Modem to point to 18.104.22.168 and 22.214.171.124 (Google) as a temp fix. Also had to do the following on each Windows desktop in the house:
In a command prompt window:
After which full Internet connectivity was restored. Awaiting Spectrum to get their DNS servers back online and will switch back at that time.
Perhaps someone knows a decent ISP near the 78726 area. This is a seriously bad sign about the level of understanding they have about their network with it being out so long. They clearly are completely lost. Could be quite some time before they're back up & running.