Sorry to totally shoot your idea down, but I really don't like that idea. I really enjoy playing through all the episode in basically one go, and I'm sure other people do to. If this idea was put in to place, we wouldn't be able to this. The way it is now, you can still do what you want to do and we can do what we want to do.
Also, I'm an impatient person. I'm literally jumping up and down in excitement (well, not literally) for episode two, and when it comes I am going to devour it. If I get to the end of the first bit I'm going to be thinking "ohhh, I need more Sam & Max now!". Which leads me on to my next point quite nicely...
...Ice Station Santa lasted for around four or five hours. If you want to release it in four parts, that's around one hour a week, which really isn't much. As soon as you've got into the game, it'll be over, leaving an impression of "oh, was that it?" and although you may think your idea will expand the length of the game, I think it will make it appear much shorter.
Finally, the episodes are like they are because it is meant to be like television shows. If you're tucking into an episode of say, Lost, and at the end of act 1 it said "come back next week for act 2!" you wouldn't think highly of it. I think that people would much prefer to sit down for four acts in one sitting for a month.
Like I said, sorry to shoot your idea down, and I hope what I said made sense - I'm not good at long (edit: I've just seen that this post isn't really very long

), explanation posts.