Not just the length to consider, but where the length is. So the distance between the hitch and the axles increases a 1' or so, and the distance after the axles increase 2' or so. The impact on maneuverability when you're already used to 35' will be marginal, IMO. The bigger question is will the overall length still fit in the spaces you like and will your tv be up to handling the extra weight. I've set my 35' trailer's tongue down in many "thirty foot" spaces, and we do mainly state parks. I don't see an issue if your numbers fit. I'd go up 3' if my tv was up to it without much thought at all. That's just me.