So it is about time for me to upgrade my phone moving from an a iPhone13mini. With the new 16 pro being the likly replacement.
I have a trip to Europe scheduled in Dec to see a lot of Christmas markets and a Danube river cruise.
So a lot of places I have never been but also more then a bit of photography in the evening/dark.
I have had good results in the dark with the IPhone 13mini (did amazing in Carlsbad Caverns for example)
I use d to take either a Canon DSLR or a Canon pocket cameras but both are getting up in age the DSLR is a XSI which is only 12 megapixels and the pocket camera is a ELPH 340 HS with 16 megapixels and a 12x optical zoom.
the 13 mini is a 12 megapixel with no optical zoom
The 16 Pro is a 48mp fusion with a 12mp 2x and 5x optic.
Arguably the DSLR and the Pocket Camera both as good as or better then the phones in anything using any sort or zoom but the phones do a really good job in low light, better then I can get out of the other two.
So suggestions?
I dont want a whole kit of lenses with the DSLR so would probably bring one lens so the advantage of better glass on the DSLR is a bit reduced. I would probably just bring a kit lens

Anyway any thoughts from those that may have more experience would be nice

I would consider the major convenience factor of not having to lug around additional equipment,

New flagship smartphones are pretty good indeed. But price wise sometimes it is smarter to get one generation older, that is usually well discounted compared to the latest one, while specs are usually very similar.

Likewise, if you want to be more into photography, some compact older cameras with good fixed lens can be fun for travel as well, like Fuji X100 series - I have older X100T and it is still fun. Or for example Canon M100/200 with 22mm F2 prime can be quite cheap on second hand market, should be less than 400$. Or Ricoh GR III is very compact and can be great for street photography as well.

My real concern is that being it will be December I expect lighting conditions to be poor much of the trip as it gets dark early in December and we will be visiting a lot of Christmas markets so and spending the vast majority of our time in various cities.
So I expect to do a lot of cityscape photography and a lot of low light/dark photos.
And I am unsure what me best options are the lower light conditions.
I have a few options for the DSLR but I have not played much with low light so I unsure what to look for/try

I prefer my old Fuji X-E2s (RAW, processed with SilkyPix) vs 14ProMax (RAW, processed with either DarkTable or Photoshop). I shoot many night cityscape and indoor (old churches, museums, alleyways, and places where flashes aren't allowed). Having a decent on-board flash is nice; also for filling in when shooting with the sun in the back. I also really like Fuji X10, which can fit inside my jeans pocket, but it is not wide enough in tight spaces like the alleyways in Chefchaouen or Fes.

@OP,
Looks like you will have a fantastic Christmas Market adventure. We did one back in 2014.
The gears you have and described will be fine. I concur that bringing less is better than more. Having said that. Here are my experiences shooting Christmas markets.
1. Purpose of your photos. For print or for social media?
2. Resolution wise, anything over 12 MPX will be fine for printed coffee table book to sharing in social media.
3. Major concern is NOISE (i.e. low light performance) and control of Highlight & Shadow. This concern supports the notion of shooting in RAW format, that allows some simple post edit. Later models of iPhone should have RAW capability, I think. I use Samsung Phone so don't know about iPhone.

Below are few examples of what I said. They are from my trip in 2014 what I shot with Nikon D90 (12.4 MPX) in RAW (NEF) format.


















I maintain a "private" Travel-Photo-Adventure web site, happy to share my Travel Journal on a Christmas Markets trip with you, use link below;

Christkindlmarkts - stefano PHOTOGRAPHY (smugmug.com)

The newer iPhone models do indeed support RAW. They also do well in low-light situations, and allow some sophisticated adjustments such as exposure compensation. They are basically good point-and-shoot cameras in a phone disguise.

Sony has a very compact lens that would be good in low light that works with both a full frame and APS-C body.
https://www.bhphotovideo.com/c/produ...m_f_2_8_g.html
Good sale on a body and lens kit that you could leave at home.
https://www.bhphotovideo.com/c/produ...s_digital.html

I've shot RAW with a Pixel 7 Pro and 6 Pro for years, still can't come close to a full-frame RAW or even the JPG out of the camera.