I am informed by quite a few folks, including one involved with the MDA Telethon, that the show coming out of Vegas is six hours and only six hours. There are, of course, little sub-telethons produced on local stations…the ones they go to in cutaways. Some of those stay on the air for a while after the national telecast is over or even go on before. If in a given city, the telethon consumes seven hours of airtime this weekend, it's because the local crew is piling on. They might even pad from the middle, expanding their segments so the Vegas part ends later. But the national feed is only six, probably-Jerryless hours.
I'm also informed that the times I gave for the telethon in Los Angeles, which I got off my TiVo, may not be accurate.