We have 5 courses at once this year, because some courses have been divided by term. But it's usually 7, so you could probably count on that next year.
We probably only spend about 10 hours a week in lecture or tutorial. But this is not counting pre-recorded lectures, which vary quite a bit because the profs aren't really bound to a timeslot anymore. I would think like 15-18 hours would be normal for "in-class" at a normal time. I personally probably spend another 25 hours a week or so on top of that to do the readings and assignments, so pretty close to 40 hours on the whole, overall. I can't stree enough that this will really vary by individual. Some people don't feel the need to read most of the cases, so will definitely be less. I'm sure some also feel the need to re-read, consult more secondary sources, etc.
There's certainly no way I could work while doing this, but I know that some of my classmates are doing it. It will really be down to your organizational skills as an individual!