It wouldn't "ruin HH". The hotel and other things are fixed cost, the only variable cost is airfare. And lets face it, no matter where in the world you are coming from we are talking maybe a couple thousand dollars for tickets. Which is extremely cheap compared to doing television advertisements that reach 10 million or more people.
I'm not sure you would qualify from Europe, since Hannover's distribution is in the US. Even if you did, it's not that expensive. I use to travel from Indianapolis to Frankfort or Munich regularly, and could get coach for under $500 roundtrip. I went on vacation to Munich one time for $289 roundtrip.