If you are going to need service on again/off again on a regular basis, prepaid is a better choice. For the $15 a month they charge you for post-paid vacation hold, you still have access to texting in Canada on pre-paid. There is no charge to set up a prepaid account and porting your number from postpaid is usually done within a few minutes. That will close you post-paid account and the balance of your tab will have to be paid on your final invoice.
Alternatively, you can interrupt payments for up to 89 days on prepaid and maintain your number and boosters without having any current service. But after 90 days, your account will be closed. Best to put a reminder on your calendar every ± 80 days to renew your baseplan if you want to keep your number active indefinitely.
To set up a prepaid account, you will need a prepaid SIM. The $20 charge will be credited to your account on activation so the net cost is zero.