Are you running on a Windows machine or a Mac? If a Mac, what operating system? How much memory do you have?
I'm running on a Mac. Some of the crashes I had were due to handling the graphics (like crashing when rapidly looking around), which I've concluded were related ot the Mac implementation by Aspyr. My friend has it even worse, on a newer Mac (with plenty of memory), but he thinks it's the graphics driver for that Mac. I found if I played in Strategic mode, I got way fewer crashes.
Note that Civ VI is a memory hog. I used to run it on a laptop with 16 GB of memory using OSX Mojave. I'm now running it on a desktop with 24 GB of memory using OSX High Sierra, and I'm getting far fewer crashes. Also, it helps if I start Firefox AFTER I start Civ. I suspect there is at least one memory leak bug -- I once got in a state where while being idle I saw the memory usage steadily climb to over 90 GB and then it crashed or hung (I forget, this was some time ago), because I was out of swap space; normally it's around 4-6 GB. I play on a standard map. What size map are you using?
Note that for me the likelihood of a crash increases later in the game with more complexity (everyone has more units, etc.). But you didn't say when it crashed for you. I have the autosave set to every turn, keeping them all (as disk space isn't an issue). Sometimes I get into a state where the save is corrupted, and I have to go back a few turns to get one which is not, but I think that is a Mac/Aspyr problem and isn't what you described.
Also, some Mods are definitely flaky. I use only UI mods, and only about a dozen well-selected. How many Mods are you using?
Anyways, it's hard to make suggestions without more information from you.