Much of the drying time is dependent on the the depth of the blisters, the amount of resin lean laminate that you encounter, the climate, and the overall thickness of the resin. In the case of the Catalina I would expect two months or so as a proper drying time.
Working with the boat upside down is much earier than right side up. Gravity is working with you rather than against you and the light is better. With keel out a roll over is pretty easy. Typically the DIY way of rolling a boat is to use a roll over rig, (two large plywood half circles that fit the hull and deck and which are braced to prevent collapse.)