I'm afraid that is dependent on your network. I have AT&T since it's generally the best in Philadelphia, Rootmetrics laughable survey notwithstanding.
AT&T is also Disney's preferred carrier and back in 2013 they
installed a bunch of distributed antenna systems and small cells on property. AT&T is generally solid at the parks, but I bet the other 3 carriers have caught up. I have noticed AT&T is
abysmally slow at the new DHS bus stop, regardless of what LTE band I am on there, but blazing fast in Galaxy's Edge (there's a hidden small cell on Docking Bay 7). Unfortunately, I don't remember how AT&T LTE works at the park entrance. I'm still inclined to trust AT&T LTE over Disney Wifi but this
post has me rethinking. I can't comment on Verizon or Sprint since I haven't had either in 5+ years at Disney World.