Yep, lots of streamed events now. If you're relying on it for the wedding, you really should go see what the signal is like with the phone you'll be using. You may get lucky and find a wifi you can work out an arrangement with. Otherwise, you may need to work with the B&G about having other guests not use their phones during the ceremony to minimize competition for cell bandwidth.
The absolute easiest & least likely to fail on you is to have an Android phone clamped over your Canon camera & use the builtin app for streaming. The app is better in that it is aware of the cell service level & can drop quality to maintain frame rate. If/when there's an issue with the stream, it is isolated from your video. If you shoot with a longer lens, add something like
https://www.shopmoment.com/lenses The reason I mention one of the video conferencing apps is that it allows folks to be seen or at least captured. You may be showing the B&G, but the B&G may want to see their 'guests'. You can capture the wedding and later show the B&G everyone else. Plus it allows for the remote guests to interact before & after the ceremony. Plus adding additional camera angles is adding another participant to the meeting.
There are more involved solutions and things that 'can' be done for additional cost, but focus on what you know you can do really well and just run with it.