I only put about 8,000 miles a year on a car (mostly city driving). At that rate I won't go for my 5K checkup until February. Should I go in early? I don't think I should be driving on the original oil for 8 months.
I would use months as your guide rather than miles if you don't drive much. For example, 5,000 miles or 5 months whichever comes first. In your case, 5 months would come sooner so that's when you should have the car serviced.