So @Neuropyramidal lets discuss the timeskip. THe comic doesn't really lay down an official lapse of time but I think most of us could agree it is at least twenty years (maybe up to 25 years).

It seems there was definitely a solid foundation laid between the Alexandria communities and the Commonwealth after Rick's death which would have only grown stronger over time. Many of the Commonwealth people seemed to go with Maggie back to Alexandria at the end of issue 192. They may have stayed there for awhile but after the relationship between Commonwealth and Alexandria grew stronger many of them (if not all of them) moved back to the Commonwealth area. THe entirety of issue 193 really takes place around the Commonwealth area so it is hard to say if Alexandria and Hilltop have been completely abandoned by the time of issue 193 or if there are still people living in that area. If there are people still living there it is likely an entirely different set of characters as all the major characters of the comic seemed to be in Commonwealth or the surrounding areas.

There also seems to have been a large scale community (maybe in equal size to Commonwealth) somewhere in the western United States as they mention finally making that connection with the western territories. I'm guessing that over the next hundred issues that we would have seen the further development of the Commonwealth as well as them discovering more large scale communities out west (as well as maybe in other areas of the country).

In terms of the Carl/Sophia/Lydia love triangle it's hard to say when Carl and Lydia would have ended and Carl and Sophia began. However there definitely were hints to a future Carl and Sophia romance being laid down all the way back to about issue 150 or so. My personal guess would be that Rick dying caused Carl to grow up a lot. It wouldn't have happened right away but I'd gander that he started realizing how shallow what Lydia and he had was and he started looking at the girl who brought real relationship prospects to the table. I'd guess that the next fifty issues would have slowly shown Carl get over Lydia and fall for Sophia. And by issue 250 Carl and Sophia would have been officially a thing and probably of gotten married shortly after.