OK. You’re going to be gone for 36 hours. About 4 of those hours are going to be daylight driving time, another 4 are nighttime driving, and some 2-4 hours will be spent in a hotel room with a (hopefully) sleeping child.
You have three current projects on the needles.
So, you should:
a) pack just one or two projects – there’s really not that many hours to knit.
b) pack all three projects, because yarn is small and squishy and doesn’t take too much room.
c) pack all three projects, and for good measure take a project that hasn’t even been cast on, just in case.
d) pack all three projects, an extra project, and think about finding a yarn shop while you’re gone.
I should be worrying about packing clothes and diapers rather than knitting, so I guess I’ll go with option c.