It depends on how you have your boat setup. If you have wenches and the ropes setup near the cockpit. The rigging. Etc. etc. Then yes, you could singlehandle a boat.
If the wenches are so close to the lines, and near the cockpit where they can hear orders from the skipper, can't they help crew the boat? Then you woudn't have to single-hand…
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s/y Elizabeth— Catalina 34 MkII "Man must have just enough faith in himself to have adventures, and just enough doubt of himself to enjoy them." — G. K. Chesterfield