Technically speaking, RTIC coolers are bear resistant, but not bear proof. There is a subtle but important difference between these two classifications. To put it simply, if a bear really wanted to get into your RTIC 45, he probably could, even if you have it latched tight.
Sometimes however a bear will simply flip the cooler over a few times to see if it will open. This might be enough to deter the bear, but more likely, it will just give you more time to scare the bear away.
Please remember to stay safe in bear territory. If you are headed into bear-country for any amount of time, be sure to read up on ways to Stay Safe In Bear Habitat.