palace15:
Yeah, it can be done. How much do you value your time and sanity?
I own an '09 G5, purchased new this year. It has been parked since June 8th with an array of defects which nobody has been eager to take responsibility for. Mind you, this is in-country, not travel, with a brand new bike that is still under warranty. Not that you'd know by the way it's been sitting. The reality of the way warranty support has been set up is that if you have a dealer who is willing to bend over backwards for you, you're in good shape. If not, you're completely and totally screwed.
I also own a 2000 Kawasaki KLR650, purchased last September. Nearly 12 years old, it has over 30,000 miles on it - 15,000 in the last year alone, and 400 more every week. It has given me hardly any trouble. When it has - and this is crucial - I have been able to source the parts I need myself and fix it, with hand tools, in my parking lot. I would feel comfortable taking it across the country tomorrow.
There are obviously plenty of people who report no issues with their Enfields. That's great, I'm happy for them. But please don't delude yourself into thinking that you can expect reliability that is even close to on-par with European bikes of this decade, or Japenese models of 20 years ago. That's not the reason I bought this bike, and I'm hoping it's not the reason you bought it either. It's pretty, it handles great on backroads, and people love it. But it is simply not fun on the highway, and I wouldn't trust it to go any appreciable distance.
So if you have unlimited time and funds to devote to this endeavor, and you absolutely must do the trip on this bike and no other, then by all means go ahead. I'm sure that good or bad, it'll be one hell of a trip. Otherwise...
I know I might be ruffling feathers, and don't mean to air dirty laundry (especially considering that my issues are still wide open). But I wanted to provide a counter example. These are great fair weather bikes. However, if you simply can't afford to deal with issues, then you're going to be disappointed.