What exactly do you mean by base riding? Tempo, lactate threshold, Long steady distance, junk miles? Base is a portion of a periodization schedule where you get your miles in at a reasonable and steady pace. The purpose is to build endurance, build up your supporting muscles and ligaments to prepare for the next phase of the schedule where you incorporate longer rides and intervals. It would seem that with 2,000 miles under your belt, your base is probably sufficient. Time to incorporate tempo, LT, VO2max and a long rides into your training.