I did my additional studying with the OU, so all the content is on line, in material sent or the lectures are at weekends, you just have to put in the effort to do it. The masters is a combination of the above, plus week long residential schools.
i have just started a fourth degree (or second masters) in regulatory science, which is delivered by the uni of Hertfordshire. With this, you pick your modules which have an intense 3 days then go and do the essays. Because I am self employed, I have made it work for me. I would expect that if a organisation is paying for you to do it, they must be supportive of the time it takes. I was sent on a management development program about 5 years ago, delivered through a university business school and was permitted to take time to go on lectures and to research a project.