I did my Lit Review in one spring semester (it was actually considered a class and if you were smart, you tried to plan your Lit Review as something you could use in your Masters Final Project). I finished the project that summer. Now, I'm a teacher so it was nice to have that amount of time to work on it.... however, I really only spent about a day each week on it for several hours at a time. I had planned to spend a little time each day, but for me, it was just easier to spend big chunks of time on it each week.
This was for a Masters Final Project that didn't really have to be defended - I just had to present it to my profs and peers and answer questions but it wasn't as stressful as an actual defense.
DH took a semester to do his Masters Thesis (engineering) but then got feedback too late in the game and ended up having to wait another sememster until he actually defended it due to the timeline.