I'll be travelling for a year. I will purchase a SIM card in a different country so I won't need to use Koodo's SIM card. But how do I keep my Canadian phone number at minimal charge so when I come back I can use the same number?
Absolute cheapest way is to port it to a VoIP service. VoIP.ms is often mentioned here, with a cost of $0.85 per month for some locations. Your next best bet is to port it to Telus prepaid for $100 per year (about $8.50/month). To stay with Koodo, either port to Koodo prepaid ($15/month), or choose the cheapest voice & text plan.