It is possible to run CAR 30 and Part 145 maintenance out of the same hangar but it requires approval.
What may yet put the cat among the pigeons is Part 135 which is supposed to do away with the distinction between low-capacity RPT and charter. At some recent workshops on the risk matrix for this level of aviation I could not get any clear answer as to the maintenance requirements for the sector.
If it is going to be all Part 145 then the howls of outrage should be deafening. What was very clear at those workshops was that there is absolutely no safety case for such a requirement.