If it's a typical ale, I also recommend skipping the secondary. Not necessary. Simply cold-crash in the primary, and add the gelatin the day after cold crashing. But I'd give it at least a few days to clarify--the longer it sits in cold crash with gelatin, the clearer it will be. When you heat that gelatin mix to ~160, by the way, it smells like a pig's ass, so be prepared. The flavor/smell doesn't transfer to the finished beer (but I've always waited at least three days, I can't say if it will given a shorter time).