Last winter we did a 10,000 mile/3 month cross country trip. When we got back home at the end of March I changed the oil and filter (2015 Forester Class C on Chevy Express chassis). I have used Mobil 1 synthetic oil and Mobil 1 filters from my first oil change. We had several home improvement projects over the summer so I only put about 100 miles on the rig since the oil change (2 trips to Chevy dealer for recalls). Other than that I run the engine every week. I let it get to operating temperature and let it run for a half hour or so. We don't have a trip planned until January. My question is should I change the oil and filter again due to the length of time since the last oil change? If yes, oil and filter or just the oil? Thanks