Don't laugh, but here is some out of the box thinking. We sold our conventional BBQ grill and bought a Traeger "portable" grill, the PTG:
http://www.traegergrills.com/shop/grills/BBQ020#.UiefZdghW6M
Think of this unit as a smoker more than a grill, and I recommend you spend a little time looking at their blog located within their web page. Now, this does take 110Vac to operate the pellet feeding auger and fan, but ohhhhhhhh, the food is fabulous!! And you must, of course, carry wood pellets to flavor with your favorite wood type; mesquite, apple, hickory, etc. The unit weighs about 35 pounds, and is admittedly not for everyone, but we simply love ours. We cook a whole chicken in about 1 1/2 hours, and smoked some savory pork ribs using the 3+2+1 recipe (6 hours cooking time, total). Or, we smoked some beef tenderloin steaks for about an hour and then seared for about 10 minutes. Viola, mouth watering, must have, experience. But, you can always go with the Weber Baby-Q.