I'm going to rent a studio for a few hours for a editorial/fashion/test shooting for the first time.

It's a daylight studio. However, the weather is kinda shitty right now where I am. The sun already goes down at 4 and its usually very cloudy. if I start a ten in the morning do I have enough available light to shoot properly (even when its cloudy)? Or is this a dumb idea? Should I rent the lighting equipment to be safe?