What is the likelihood of working full-time from home as a tax accountant? Should I pursue managerial accounting instead?
Being a managerial accountant is not a specialized position and may be more difficult to be able to work from home. But, so long as you work for a good company and your work gets done timely, you will be allowed some flexibility with your hours.
I can't speak for managerial accounting, but flexibility is becoming increasingly common in public accounting. While it may be difficult to find a starting position allowing you to fully work from home, it will be easier to find one that allows you to work some days at home or choose your own hours. During the Spring and Fall busy seasons, it may benefit you to be in the physical office, so that you can work with your teams and be more efficient. However, your day-to-day schedule can usually be split between the office and home to fit your schedule and lifestyle.
I think that in either field you can find an employer who offers flexibility. It would be rare to find an employer offering full-time work from home abilities, however not impossible, so you should search for this online. If this is not easy to search for, I would say that many companies likely do offer flexibility to do this some of the time and to talk to recruiters before applying.