I am an independent writer/director and owner of Infested Films, a production company specializing in horror and practical FX.
I've had this discussion numerous times with friends and colleagues, and I believe there is no "correct answer". Working in film/TV, especially in key positions (Director, Producer, DP, etc) is a way of life. It is a passion that requires not only your time "on set", but your whole life. It never sleeps. If you can find someone who either shares that lifestyle/passion, or is willing to commit to it with you, you will be fine. Just as long haul truckers, loggers, journalists, etc find themselves away from home/family for months at a time with sporadic schedules, creative types and people in the film industry can find a balance that works for them, provided they find someone who shares their wants and needs.
No relationship is "easy", regardless of you or your spouse's profession. It's all about a healthy balance and a mutual love and respect for your partner and their passion(s).