Look if the company decides not to hire more engineers. That doesn't mean you go and spend 80+ hours to finish everything!!! If they don't hire more engineers, they're telling you that the work you're doing is of limited value and you should act accordingly. and if that means a project takes 3 times or 4 times longer then so be it. That's their decision. You have to set limits according to your job description and your work/life balance and make enough time in your work week for mental sanity (maybe some meditation or walk in the park time). that's all part of the job.