There is a select few clients that I will pick up the phone for anytime day or night. These are typically the larger projects that have homeowners who I get along with. If I can't get to them right away they are usually very understanding. As soon as I get a signed contract, I normally put all that client's contact info in my phone, that way I know who is calling and can choose to answer or not.

The 9:45pm NYE caller called from a number I didn't have, like he knew that I wouldn't answer if he called from his cell or home phone.

I am too old and probably too broken for a career change at this point.
A few years ago I tried to make what I thought was a smart move, getting out of the field and working as a PM for a large, successful CI company.
Yeah, that didn't work too well for me. Having to get up at 6:00am, drive an hour and sit at a desk almost all day felt like a prison sentence to me.