Well, after a few hours, we made it!
We spent some time in Niagara after the landing at the Rainbow Bridge wasn't processed. Instead of going to the same bridge, we tried the Peace Bridge - it was almost 11 pm.
Once we got there, the officers said it would take about 6hrs. It took less than 2.5hrs. The only problem was the wait. The landing itself was fast and simple.
The only additional document they requested was some proof of address for them to send the PR card. By the way, the estimate time for the card is 6 weeks.
That's it. If you need any information about the landing that I can help with, just let me know.