You will find training schedules for novice, intermediate and advanced runners. Nevertheless, it is possible to double up and run two or more marathons within a short period of time. In fact, I devoted an entire chapter in my book Hal Higdon's How To Train to that subject. Well, marathons are fun. There's an excitement to traveling to some far-off place to run before cheering crowds.
Nobody can deny that Honolulu is a great destination marathon.
One way to run multiple marathons is to not take the races too seriously. Don't try to set Personal Records. He advises that multiple marathoners program one easy week after their marathon efforts. Depending on how you feel, this might mean substituting walking for running. The final week before the next marathon is a tapering period to gather strength.