Just my 2 cents, but I much prefer Propel over LiquidIV - both the flavor and the ease of mixing/size of the packets. We try to travel light in the parks, so I wasn't wanting a pocket full of the LiquidIV packets. I got both at
Walmart.
We were just there last week and of course it was hot. I would do just one or two bottles a day with the Propel added. Then I'd have plain water, maybe add some TrueLemon, and usually get a refill of whatever I drank at lunch. Seemed to work well.
Good luck with whatever you decide and enjoy your trip!