Honestly, I do the turns lock to lock solo just fine, no I do not have a full size Ultra, but then I have only had my Sporty about a year and is my first Harley. And no I do not get enough practice on the bike with Coline on the back to do this on a regular basis. BUT since I am only a block or so away from a parking lot, I usually do a few left and right figure eights lock to lock just to keep me "fresh" before I go on my weekend rides solo or 2-up as a warmup, especially if it is at the beginning of the riding season.
Yes, I have had to do tight turns w/ Coline on the back, lock to lock...but I made sure I did it smooth with weight on the outside peg, knee against the tank and did it without drama...make sure you tell your passenger early on when doing slow maneuvers to always be still, and keep sight line with my DOT sticker on back of my helmet. You do not want to scare the passenger, so smile to as you do these manuevers, keep mentally focused and look all the way around the turn, DO NOT look down. Use your friction zone on the clutch, keep the wheels moving and use ONLY the rear brake...you will be fine!