If you don't live near an In-N-Out but really really really really need some Double-Double action and you have some money to burn, online food store (specialty: "the best" hard to get foodstuffs) Midtown Row is selling In-N-Out Double-Doubles (in Classic or Animal Style), freshly frozen with overnight shipping for $50 per two burgers (plus $6 flat shipping). Order before 11:59 p.m. PST on October 31; the burgers ship on November 1.
Their description says "We will ship with proper refrigeration via overnight mail, but reheat and consume at your own risk." Good thing Kenji has frozen Double-Double reheating advice:
After a totally failed attempt at reheating one whole, I realized that the best way is to separate it into individual components, and reheat each individually, tossing the veg and replacing them with fresh ones.
Then again, he went through all that trouble to give you a fantastic Double-Double Animal Style recipe to try at home.