As long as you use commercial financing, you will not hit a wall. Your income does not matter for 6+units buildings.
Finding a partner is a good solution. You have money but no time? Find someone with time. Go to your local RE monthly meeting (CIIQ, Immofacile, mordus, etc). Do you speak french? If you have capital and go to Immofacile meetups, you will have A LOT of offers from active investors looking to scale up with more capital buying big deals and offering 50% of the pie to people with money. Investors with the contract get a great deal with 0 downpayment but have to structure, manage and stabilise it all, you get a great deal with 0 time invested. It's exactly the structure they teach there at Immofacile. Very win-win, I like it a lot.
I did the CIIQ coaching program and it helped me a lot (from 2 to 9 doors in 1 year, last 6 units is already ready to refi and take out my downpayment to buy another 6 units, but I want to buy bigger...). I'm starting to like Immofacile's approach more, you buy bigger/better assets this way and for someone like me who has a lot of time, it allows me to always be looking for deals, instead of waiting for buildings to refi to keep going. I am in the quebec city area, if you are interested in buying around here, we could connect. I can probably give you a few names of investors who structure deals in montreal if you only want to invest there, just pm me. :)