hempy bucket size question

1 gallon hempy bucket
1 week into 12/12 - started showing sex
Strain: Special Kush #1 from Royal Queen Seeds
Lights: 150watt hps/mh

The plant is a good size for my lights; I've topped and LST'd; but I'm afraid 1 gallon container isn't gonna cut it when it starts to bud properly. Do I risk it and make it a pathetic attempt at transplanting to a bigger container? (I'd like to make the most out of what it yields)

You be fine with 1 gallon. You will probably have to water everyday during flowering though. I did hempy with 2.5 gallons with great success. I watered around every 3 days. I recommend feeding with foliage pro at 1/4 tsp every time, veg and flowering, since your going to be watering daily.