Cave Summary: This is the easiest cave in the game. 3 treasures and 11 snow bulborbs. Too Easy. Recommended: As many Red Pikmin as you can get.
Sub-level 1
Defeat the Snow Bulborbs. They shouldn't be too hard, attack with pikmin throw/punch. Get their bodies for minimal Pokos. Also, get the Orange and Bottle Cap. Then go to Sublevel 2.
Sub-level 2
Defeat the Snow Bulborbs. There are 7 of them, but still not much of a threat. You will notice a globe. You can't lift it with 100 pikmin. Hmm, here's a puzzler...you can't lift it without 101 pikmin, but you can only have 100 on the field...how do we do this? Purple Pikmin! Duh! You'll find Violet Candypop Buds near the exit. Throw in 10 Red Pikmin. The violet Candypop will turn them into Purple Pikmin. Pluck the Purples and grab the treasure. Purples can lift 10x as much as other pikmin. Also, they can stun enemies when thrown. Beware their slowness, however. Grab the globe. It will open up Awakening Wood. Leave through the geyser, but be sure to pluck planted pikmin. Congratulations. You just completed the easiest cave in the game!