run time question

im not saying im going to go out and buy a 2200kv cc motor today or anything. i just wanted to know for the future. the mains im going to be running right now (beginner) only run for 10mins and i can run a 10min main racing just fine. but soon im giong to have to bump up a level and the mains will be 20mins. and i know right now i cant run a 20min main on my motor and battery setup i have. i was just wondering if a 2200kv motor or a lower kv motor would help me do better then im doing now. i know i will not be able to run a 20min main no matter what. but trying to get as close to it as possible. (the track owner sometimes lets us brushless people start later or lowers the mins to 15. )