I have no advice to offer other than this: When I came over here over seven years ago, it was the end of the month/beginning of the next, so I had movers put ALL my belongings in storage.(I planned to come back, stay with one of my brothers until I found a place that would accept a cat, etc.) I didn't plan to stay in the U.K for more than two weeks, but once I met my husband face-to-face, I knew I wouldn't be returning to the States in two weeks. We were kindred spirits. So I stayed, and to this day, all of my furniture (sofa, loveseat, and glass side tables and coffee table), cool lamps, marble dining table along with seats, not to mention a brass queen-sized bed and countless books and family photos, very expensive prints on the wall, etc., are still in storage. At first, we were paying $139 per month for storage; now it's $179-plus dollars per month. We've probably paid more than everything's worth, but my furniture and bed were only two years old when I left, and in perfect condition. My husband thinks we should default on the payments after all this time, at which point everything I own would just go up for auction, but I won't go for that, because if I DID, I'd have nothing to go back to in the States, if the worst happened.
You haven't explained why you'll be here for just five years, but if you're here for romantic reasons, I wouldn't bother shipping all my belongings here, given that he's already fully furnished, I would assume. I made the mistake of putting my stuff in a crammed outdoor storage space. I have no idea how the temperature extremes in the D.C. area have affected it all. If I were you, I'd put my belongings in an indoor, climate-controlled storage space. I hope this rambling message has helped you in making a decision, either way. HOWEVER, I'D ADVISE: DON'T BRING ALL YOUR BELONGINGS HERE--YOU'LL JUST BE ADDING SURPLUS TO WHAT YOUR PARTNER HAS, AND I DON'T THINK YOU REALIZE JUST HOW SMALL FLATS (APARTMENTS) AND HOUSES ARE HERE.
Good luck.
Suzanne