I went from a 27 footer to a 33 footer, primarily single-handing both. The 33 displaces about twice what the 27 did, so in theory I have twice the boat to handle. I agree with what the others have said about the bigger boat being easier to handle. My take on it is that the bigger boat is more foregiving in most ways compared to the smaller boat because of the slower reaction time. And as for docking, follow the adage that you should only approach the dock at the speed at which you'd like to hit it. In other words, slow and steady coming and going. My experience is that leaving and entering the slip are the two toughest things about single-handing. Once underway it gets easier -- and get an autopilot
One last tip for docking -- practice, practice, practice. Study how the boat reacts at slow speeds both in forward and reverse. If it has propwalk in reverse, don't cuss it -- learn how to use it to your advantage.