If it meets with your normal maintenance, I'd get it changed right after, but remember that even though the trip will be 2300 miles there and back, you'll still have running around mileage as well. We put over 6000 miles on our car for a road trip we took several years ago, and that was with a one way distance of 1800 miles to get to our destination. If you are expecting mileage like this, I'd get it changed before hand and then start your maintenance schedule at that point. Highway miles are easier on your vehicle than stop and go, but they all take their toll. Make sure which ever way you go, you do a thorough check of all fluids prior to leaving, to include oil, transmission (Odessy's are known for transmission problems), coolant, windshield washer fluid, and whatever else you can think of. For anyone's edification who may be wondering, the normal oil change interval for a Honda vehicle is every 7500 miles.