@Dolby1000 Not only do I have the G6, but also use the Tandem t:slim X2 which is tied to my G6. No need for internet at all. I’ve also used the Omnipod 5 with my G6 without issue. Started with G4 , then G5 all without issue.
side note - have Dexcom troubleshoot your wife’s connection issues. I’ve only had issues when phone or app needed updating, when transmitter battery on sensor needed replacing, or the occasional phone rich environment. Moving phone to that side of body always fixed it.