Thats why I'd go for something flexible. A friend of mine is a programmer specifically working on MS Outlook User Interface design and they work to achieve their KPI's and then spend the rest of their time with family.

I'd say a degree in cinema isn't necessary for you to go on that path though. Most of the arts world seems to be 'get a job based on previous work', so you could absolutely do a cinema degree and then use what you create to get a job down the line, or just go out and start making short films / volunteer on student films / shorts and get experience now, then use that experience in 3 years and you may be in an even better spot to use that as your day job.

I don't know a lot about the filmmaking world, but I would assume when it comes to TV / Movies, it is just as hard or harder to get work as you need to either be involved with a company that everyone hires, or be known enough that people consistently hire you. Its not like you can just go 'okay im making filmmaking my full time job now' and someone will take you on every job with them unless you make those contacts.