If your engine doesn't leak or consume lots of oil between oil changes, you could stay with the grade of oil that got you to this point. If you have to keep topping up between intervals, you could try a thicker oil or the high-mileage oils. In addition to having a seal conditioner, the HM oils usually have more detergents and additives and are usually a little thicker than the same weight conventional oils.
Some have had success stopping or slowing leaks with Castrol and Pennzoil HM oils, others haven't. I'm currently trying to stop a slow weep from the rear main seal of my daughters Protege with Valvoline Maxlife. If it doesn't work, I'm trying the Castrol HM next. I don't have to add any oil between 4K changes, but I'd sure like to stop it before it becomes worse.
BTW, I'm still running 5w20 currently in my Accord. This is what Honda spec'd for my LX back in December of 2000. See Sig for mileage.
