As long as the Oil Pressure dash light did not come on, the engine is fine. The Oil Pressure warning light would have meant oil flow to the engine was stopping, which can quickly destroy an engine. With oil that low, internal oil temperature got high. Synthetic Pennzoil handles that well. Yep, check the oil once a month, on level ground, in the morning cold. Using 5w30 syn in an engine originally designed for 5w20 is no problem in this case. Actually, Pennzoil Platinum 5w30 is almost as thin as a 5w20 hot anyway. You made a good choice using that. Probably the best value in a full syn 5w30 oil is the Walmart SuperTech 5w30 full syn though. I'm jealous of TX mild winters where you don't need to haul around the extra 4WD parts mass & MPG penalty just for the hope of not getting stuck in the snow. Smart to have a 2WD Patriot there.