Is it unreasonable to want to join a startup but not work over 45 hours a week? I will not promote

I’m very interested in joining a startup for my next role but I’ve heard such horror stories about 9/9/6 and the WLB - my current role is very nice, remote, high WLB, but I don’t have much ownership or impact since it’s a big tech firm. Is it unreasonable to want to join a startup but not lose my soul? I’m asking since if it is unreasonable, I may stop searching before I even start For more context, I’m looking to be one of the first finance hires for a green tech startup between Series A and C.