It varies by banks

For Scotia, you can convert LOC to regular mortgage with any term and any amortization. Of course, the max amortization is 30 years now. But for one mortgage plan, you only can get 3 mortgage accounts, the rest must be LOC, which has higher interest rate.

For TD, you only can convert LOC to fixed term mortgage with max 25 years amortization. Not sure TD allows how many mortgage accounts.And TD's LOC rate is P+1

The good thing for LOC is that whatever you pay back, it is there for you to borrow again, and you can pay whatever amount without penalty. The bad thing is higher interest rate.

Not sure other banks, you can ask banker accordingly.