We already have a day off on the 30th for CLC/fed regulated people plus labour day I doubt there will now be THREE in September in perpetuity.
*******
As for costs.... I argue the current system is actually more cost effective. We do not pay tribute to the crown, instead we pay when they are specifically representing Canada and of course the costs of the GG etc.
Adding an election for a president is a $300M cost every four years (rough fed election taxpayer costs). We pay in the area of $40 to $60M per year for the GG, crown, etc. but this is not their pay it includes the cost of travel, housing, staff, the cost to host dignitaries, foreign leaders, etc. which we will mostly pay monarchy or republic (so this value is misleading). So we add $300M every four years to get a say on "who" but still also have to pay most of that $60M per year anyway???? Even if we could save the entire $60M (not possible we will only shift the line items to other departments) that is $240M over four years vs $300M for the election. BTW most functional republics have the equivalent of a PM and a President which one is week and strong differs. There are functional reasons for this.
One argument is that we just have a PM and no President to replace the role of the crown.... I don't want Trudeau to have more power, do you????
BTW it is a good question for PP.... as Conservatives support the crown more than the left.