I would say 4 or 5. I"m not really familiar with that brand, I just know for 2 of us, we used to bring 3 cans and come home with just over 1 full can. I'm also allergic to a lot of things so it's safer for me to bring what I know works and not buy anything random I can find when I run out.
Something we've been using lately is also carrying around some of the handy wipe style sunscreen, sunscreen w/bug spray and sunscreen specific to face and nose. we find it's our faces that tend to get hit the worst and feel before it starts to feel or show elsewhere. An alternative to sunscreen with bug spray is look for a brand that include aloe in it. While also soothing a little if your late putting more on, aloe tends to repel bugs. You don't really need to worry about bugs around disney, they have amazing pest prevention but there are some areas, especially areas like boat docks we were regularly see them flying around light posts.