Powerful individuals such as Gandalf and Aragorn travel with the Ringbearer over a period of months without being corrupted by it. "
Sure, but the argument then becomes that Aragorn and Gandalf never get anywhere near
Mount Doom with the Ring-Bearer.
Remember, Aragorn never intended to go with Frodo to
Mount Doom; in the book, he was going to depart the group and go with Boromir to Minas Tirith. The death of Gandalf, and later, the capture of Merry and Pippin force him to postpone that event.
-wtk