I would doubt there's really anything more reliable than those various "istheservicedown" type of sites that come up in Google.
Most internet outages are either localized entirely to your own line and house/hardware, or a small neighborhood when there's problems with a particular node in an area. Rarely is an outage big enough that an entire ISP or city is down and will have massively widespread reports all over websites. Best bet is usually to just call their support line.
Depending on your ISP, there might also be a dedicated support sub-forum for them on dslreports.com which has a pretty big Canadian section of their forums too.
Source: It's been over a decade now, but I used to be a small time ISP support guy "back in the day"
You can set up services like https://uptimerobot.com/ for free to check on any web address at regular intervals by ping or by http. People use them to monitor their web site and make sure it stays up, but you can set it to ping your home IP address and make sure you are reachable. Just remember to enable ping response on the IP address you are trying to reach. Many internet-facing routers have ping response disabled by default.