Here is the rule about suitcases, coolers and backpacks from Walt Disney World themselves:
"Suitcases, coolers or backpacks with or without wheels larger than 24" (61 cm) long x 15" (38 cm) wide x 18" (46 cm) high. Coolers required for medication may be stored in a locker or at Guest Relations"
Prior: Offsite most every other years from 1972 - 2000
Most recent: Offsite 2001 & 2003 / ASM 2006 / Offsite 2009 / Poly 2011 / POR 2013 / CR 2014 / GF 2015 / DS Hotel 2017 / BC 2017 / POR 2018
