I'm not that familiar with the new course, but I think the above poster is correct - Law (hons) is a lot more structured, so it's probably not feasible in that sense.
In any case, I wouldn't recommend doing 4 law units in a semester. I was also a transfer student, and I made the mistake of getting all my commerce units 'out of the way'. In the short-term it was okay of course, but in 4th/5th year I then had to do 4 law units for three semesters. Not fun, especially when the exam timetable doesn't go your way and you end up with a Corps law exam on day one, followed by Trusts on day two, plus a proposal by an elective to hold the take-home exam during SWOTVAC because of a bureaucratic f*ck-up by the exams dept. (which luckily didn't eventuate cause everybody complained).
I think you'd be better off balancing out the commerce and the law units. Where doing 3-4 law units is unavoidable, try and get a good split in the law units in terms of cores/electives, harder subjects/easier subjects - don't try and cram equity, corps and admin into the same semester, for example. Also, consider doing a summer unit or two to lighten the load, some are easy and can be done quickly (e.g. Negotiation & Mediation is a one week unit, other units are also often taught intensively). They won't intrude on your break all that much, as one would imagine, a unit isolated by itself doesn't tend to be nearly as difficult as juggling four at a time during S1 or S2.