As far as what I have read on other diabetes forums, people are not liking the G7 at all. They have problems with both accuracy and longevity of the sensors. There is a new 15 day G7 sensor that is just about available in the US and that sensor has an abysmal fail rate reported from Dexcom themselves.
I have been using the 10 day G7 for about a year. I'm just one person so my experience is purely anecdotal. I haven't experienced the problems other have experienced to the degree they are seeing them. In that year I have only had two sensors fail and they were both quickly replaced by Dexcom with no hassle. I have had accuracy problems, mostly in the first 12 hours of changing to a new sensor. Those instances have been frustrating and much more frequent than sensor failures for me. Usually the difference in glucose between a finger stick and the CGM is in between 20% and 25% when they are being inaccurate. It's a big deal but not the end of the world. I can usually get it sorted out with a calibration. I have seen others post their CGM graphs and theirs are wildly wrong so I may just be getting lucky and your mileage may vary.
And to answer your question, you cannot restart the G7 like you can the G6. That would have been really nice. Anyways if you end up on the G7 in 2026 I hope it works out well for you. Or at least as well as it has worked out for me.
It appears that Medtronic will continue to manufacture and support the Guardian sensors for the foreseeable future. Here is one of the Medtronic executives talking about it. I have timestamped where she is talking about Guardian but the whole episode is pretty good if you are curious where Medtronic is going with its 3 different CGM sensors in 2026. In case the timestamp doesn't work she talks about the Guardian sensor at 21:22.
https://youtu.be/ai-E5Ch7Y1c?t=1282
Hopefully I linked that correctly. I'm pretty new to Piefed. If it was me personally and I had the option I would switch to their newest sensor, the Instinct. It is made by Abott and is essentially a Libre 3+ as far as I can tell. I am currently using the G7 but I used the Libre before that and I really liked it. Very accurate and a long wear time. No complaints really.
EDIT: Inserting an URL didn't work. You may need to copy and paste my link. Sorry!