I'm trying to depart today about 20 hours before my scheduled departure. THe rule says you can 'standby' when your original fare code is not available. With most fare buckets opening up ~3hrs before a flight, It would be easy to confirm my MCO-IAH flight. However, factoring in the 2.5 hours to IAH and the schedule of onward flights to SDF, the connection won't hit the 3hr mark at the time I'm trying to leave MCO.. Will they let me go as far as IAH and try my luck to continue from there today- I would stay at IAH at my own risk. Or will they say they can only clear me to IAH if they can also clear me to SDF?

thanks.