There are lots of that description in Cornell. Most of them are 9 or 10m lots, but there are a lot that are 6 or 7m frontages.
You can't really go skinnier than 7m or so on a detached home since you need a side yard - 0.5m side yards on a 6m lot only allow for a 5m wide home, which is starting to get too narrow to really function properly.
Road widths can certainly be reduced - Markham uses a 20m ROW. Toronto's standard is 18.5m with an 8m wide road.
Below 8m or so is troublesome for bidirectional traffic after getting in a row of parked cars - so once you get your sidewalks and grass medians in, 18m or so is about as thin as it gets.
If you are will to do one way streets you can get it down by another 2 or 3m, but that causes other issues.
Most old Toronto streets are actually 18m ROWs anyway - the big reason they feel much smaller is because the trees are so much larger and often only have 6 or 7m roads.