Hi Groopp! And welcome to CR forum!
You want a light compact camera that should also be good in low light.
When it comes to size a PowerShot G7X could be a good solution, like you mentioned in first.
If you worry about the Mark II beeing somewhat old there is a slightly more expensive Mark III as well.
If "low light" is "the main reason" as you mentioned, then think about an APS-C sensor instead of an 1" size.
My travel setup is a 200D/SL2 with the two pancake primes EF40 STM and EF-S24 STM.
Today there is the newer 250D/SL3. Or you can go smaller with an EOS M body, like privatebydesign already said.
Both of course bigger but also with bigger sensor = more light gathering.
Good luck with your choice.
There is a good argument for the G cameras in terms of low light. The zoom lenses are f/1.8-f/2.8 over the range. Traveling with APS-C, lenses that fast become even less convenient. So there is a trade off. Larger sensor sizes let you get away with higher ISOs. Faster lenses let you use lower ones. I find the noise level acceptable up to ISO 1600 on the G5X II. Stabilization lets you use slower shutter speeds, depending on focal length. With that camera I made handheld shots from the balcony of my stateroom on a moving ship as we left Venice as it got dark. The pictures were amazing. There was some noise in the night sky that was easy to tone down, since there was no detail to lose. I printed on my usual 13” x 19” paper a shot of the Doge’s Palace, the top of St. Mark’s, and environs from the canal we were traversing. It looks great.
For me the choice of what camera equipment to take is based on the purpose of the trip. If I take a bunch of gear, the trip becomes a photo shoot, no matter what I intended. If my purpose is to go places and do things and just incidentally take pictures, then I just throw my G cameras in the bag that fits under the seat on the plane. I still took over 3,000 pictures during the fall, 2019, trip that started with a bit over two weeks in Italty followed by a 14-night Mediterranean cruise. But picture taking didn’t distract from my activities, most of the time. (OK, sunset on Santorini became a photo event.) And the camera fit in my jacket or pants pocket. The only time I missed having more gear was in the Pantheon when I took pictures of the dome to stitch together back home. I don’t know that 16mm on my full frame or 10mm on my Rebel would have taken it all in, but at least it would have been fewer shots. For me, that wouldn’t have been worth carrying a bag full of stuff.
So I would say that in addition to technical considerations, one needs to consider personal style, habits, purposes, etc. In the nineties, I quit taking a camera with me at all when I traveled. In 2000 I had become less serious about photography (or less obsessed), so I thought it was OK to take a basic camera along. That has worked out well for me since. And my “basic” camera has become rather sophisticated.