I suggest that you panic
/s
Think of it as a big regional. except there's 6 of them going on at the same time. and the venue is gigantic. and the whole experience is fantastic.
With a bigger team, we were able to scout as normal the two years I went to champs (and in 2013 there were 100 teams per field, if I'm remembering correctly); everyone had to take on a few more teams than at our regionals/DCMP (and a lot more than our district events), but not many more. this might be different if you're low on people. Pit scouting would be a fantastic idea if you have the manpower; to be able to see all the cool stuff people come up with up close is something all the scouts should get to do - every person who goes there really. even if you can't scout in the pits, at least try to get a picture of all the robots so you can get an idea as to their functionality.
There's no reason why your field scouting should change from earlier, unless you think there's something you can do better than you did last time.
Keep in mind that every team that is going to CMPS has had at least 1 event - district teams at least 3 - so there should be video of most, if not all of the teams. utilize this to do some pre-pit scouting, or to replace your pit scouting if you just wont have enough resources for that.
in the end, though, it just depends on how much work youre willing to put into this. if you chose to collect all the pit scouting info, and you know it'll take you until 3 in the morning to compile together all that information, you can choose to stay up, or cut back then (whether it's because you're too tired, or pretty much guaranteed to be a 3rd/4th robot, or whatever). if you chose to not collect that info, you cant decide that you want it later.