I have a Nikon D5500 with 10-24mm lens. Amazing picture, I'll shoot RAW and then editing in Lightroom. But, it's a large camera. Not very heavy, but just large. On one of my expeditions, person had a Sony RX100 III. We did share emails and he was kind to share his pictures from from the trip, again, he used the RX100 III. Amazing. Pictures were great. He told me that pictures in low-light will not be as perfect as with the Nikon D5500, but quality of the RX100 is great. And you can shoot RAW. I have been looking and RX100 III got for $350-$425 on Ebay.
I also looked into Olympus TG-6, terrible!!! JPG and RAW, just terrible.