It is of more concern for the lender than CMHC I think. So the correct anwer would be "it depends"
It also depends on where you are financially/credit/debt. If you already have the mortgage, you should be able to do what you want with it, rent it or whatever, the problem would come when you want to renew your mortgage, again....where are you financially, and with your credit and debt or what you would qualify for with your current income.
I would suggest you sit down with an (investment) mortgage broker (there are lots here or I could refer you to some) and come up with a "plan" for you to figure your stategy over the next few years...then you will be following a "map" that might allow you to get where you are going faster...or even figure out where you want to go.
My short take on your situation is I would suite the property, get the rent up, then sell it for an increase in value (I assume you bought it at a reasonable price) take that equity increase, go into another principle residence (you just saved some tax there) with more down payment. Do that a couple times and you will not need CMHC to insure your property, in fact, I think (just my take) that you should get some equity under your principle residence before you go chasing investment properties. With the savings of tax on priciple residence gains, that is some of the most lucrative income you can get. (then you can put a LOC on it an use that CHEAP money to finance your investment property aquisitions) but that is just my idea.
...and there is more ways to approach this than you could imagine. But it all starts with a "plan."
Good luck, this can be a very interesting adventure!