I advise against going with only one screen and split it with software. I thought this was a good idea and replaced a dual screen setup with a 37,5" Ultrawide.
But I found it to be very impractical in the end.
It's just different than dealing with two separate screens, I couldn't get used to it. In the end I kept the Ultrawide for the edit window, which is really nice, but still added more screens.