Vodacom/Telkom prepaid VoWiFi work like a charm overseas (for me, at least).
In fact, I keep roaming deactivated to make sure I still pay local rates.
Not sure about this solution long term though.
I have a spare number I’ve been parking on one of my rainOne sims that I want to start using.
If I port it out, will the SIM get assigned a new number (as I am paying for it, after all)?
I’m aware Telkom assigns new numbers to SIMs after a port out, even if it’s just regular prepaid.
Works perfectly internationally, I've even turned roaming off in favour of using it full time (for SMSes mostly. Calls work fine but there's always a bit of latency)