The workload at most schools is about the same. Most law school classes are set up so that your entire grade rides on one exam at the end of the semester. It's up to you to decide how to spend your time before the exam.
Legal Writing is different because there are a ton of deadlines for multiple assignments during the semester. Whether or not your LW prof decides to grade these assignments, it is still mandatory that you complete them. Then you have a big assignment, usually an appellate legal brief that counts as your final. It will either count for your entire grade or a large portion of your grade.
LW at law schools usually sucks because the profs are particularly bad. They all have their own pet peeves and little quirks. Doing well in LW isn't usually about being a good legal writer, it's about conforming to exactly what the prof wants. Most students find this frustrating so they don't like legal writing. Then when they get out in an internship or post-grad job they figure out that a lot of stuff their LW prof was total crap and they have to relearn everything on the job. Sounds fun, right?
I for one, would not have wanted to take 5 semesters of legal writing. Most schools only require one year of legal writing during the first year. Then, you are required to take 1 upper level writing course which usually involves writing a scholarly legal paper. The paper is completely different than the memos and briefs and such you do in first year LW.
If you're wondering about the workload at this particular school, my advice to you would be to talk to a mix of students in the part-time program. Find out when classes are held, go there, and talk to part-time 1L/2L/3L/4L students and see what they say. Another strategy would be to get permission from the school/profs to sit on on classes. Find out what the assignments are and do the work for a week or two. If you're having trouble keeping up, well, you just found out law school isn't for you and saved yourself a semester's worth of tuition.