I do this pretty regularly (also convert muffins to quickbreads and back again). You definitely don't need to adjust the oven temperature. Obviously the time is less but I can't give you exact numbers because I'm terrible about writing them down. I usually start at about half the time (probably a few minutes longer than half) and then start peeking. Assuming you know what your muffins are supposed to look like (how gold they get, etc.) it works pretty well.
Also, Oreo was my first cat ever. Love the handle.