Yes, you can
Yes, you are allowed
Probably depends on how big it is did see some people with coolers with wheels on them
Yes
Yes you bring it
Just put it in your bag and you shouldn't have a problem
All bags are checked. I am not sure what a yetti is. However we are allowed to carry food and water into the park
We brought a small bagpack full of snacks and bottle water and we had no problems.
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