The same could be applied to her hearing aid. Assuming she wore it during the day and took it out at night, a NY Times article said they were in her home. Would indicate she did make it home and was in bed.
I believe this is the article but it's behind a paywall. If you search 'hearing aid nancy guthrie NY Times, you can see it's mentioned it was found in the home. (no idea if it is true and AFAIK, it's the first mention of it)
The mother of the “Today” show host Savannah Guthrie has not been heard from since an evening of dinner and games with family members.
www.nytimes.com