Thanks for your reply Brian. Plainly this will not work for full resolution TV in either HD or even just SD. I was creating 640×360.
This is no substitute for a full multi-camera shoot but I was surprised how much more interesting and dynamic it looked (in my humble opinion) than just using the one downconverted shot for the whole piece.
Quite a few people must end up with a recording that they could try this out on. Even if they have shot with several cameras if you have a complete recording from one wide-shot camera you could give this a try and see how it looks. I prepared the three downconverted versions before the edit so that I could switch between them easily. Two were fixed and with the third I actually moved the selection so some shots even have the effect of camera movement.
Working amateur
Panasonic Camcorder 1080p, Nikon SLR with video acquisition 720p, Sony Vegas editing software.