I have travelled the Thames single handed from Reading to Oxford, and vice versa, quite a few times, but usually in late Spring or early Autumn. I never had any problems and the Lock Keepers were always very helpful. I always preferred to get off the boat and hold it on two ropes, and was only ever told to switch the engine off once, and that was by a summer relief keeper. When I tried to explain that it would be difficult now I was off the boat, he got very authoritarian and did not like it when I indicated that I was steering Narrowboats before he was born. The full time keeper then came across and said it was ok for me to stay on the lock lockside, adding that "these narrowboat skippers know what they are doing"