I did the opposite way - from DSLR to 4X5.
Since before using DSLR, I was shooting mainly 35mm, I looked for new experiences and the 4x5 was the answer.
The way I see it - I don't need many photographs. I took a lot and now I am interested in a certain look and feel. However, when I work commercially, time is paramount and I'll do anything it takes to finish the project on time. Therefore am using DLSRs for the majority of assignments.
I do not carry a small point and shoot at all times, and don't feel I need to be always on alert. However, when I shoot for pleasure, the 4x5 fills the need. Not so much for sharpness, but the camera movements make the pics look differently.
My advice - you don't need to sell your LF equipment - just buy a DSLR and use it for a few months. But aside from landscapes, maybe with the DSLR, you can switch your focus and take more candid pics or do some photojournalism. A Nikon D700 can be an eye opener allowing you to work at very low light levels, but for max resolution, you'll need the top of the line from Nikon or perhaps a Canon 5D Mark2.