Now, I feel kind of awkard answering this, since I am nowhere near a 3:35 1500m. However, it kind of depends how long of a break you are taking. If you took the whole summer off, then you better start up now. If you ended your season the end of August. begining of September, sure you can start up again mid October. A good healthy month long break can be very beneficial. Morceli did this, many Kenyans do this. You could get a good base in October-Janurary, a few indoor races Feb.& March. Then go after your 3:35 April and May.