Reader's Digest version: Neither.
Explanation: (Disclaimer - have never done what you are preposing to do.) Bought my pre-'08 KLR from someone just returning from a Tierra Del Fuego/Alaska ride. 9 months and 35K miles I think. Bought it virtually sight unseen. First question when we met was "How do you take 9 months off to go for a ride?" Followed by "Are there any openings?" I would take that same bike and do the same trip in a heartbeat if I had the time.
You have 27 months. You're willing to throw a bike away and buy an Enfield to get back so I assume for you this is about the ride and not about the bike.
Consider a pre-'08. Take the 27 months and become familiar with the bike. Use the funds that would have bought brand new and set it up with whatever accessories you think you'll need - (luggage, handguards, larger front disc and doo for example.)
Ride it. Ride it some more. Go on some ugly roads. Pick it up once and a while. Ride it some more. Make some adjustments now and then. Ride it some more. Fix broken things. Ride some more.
Most of all, take your time and enjoy your trip.