As you note, the oil sands industry has two main approaches to recovery of the bitumen. One is mining, which is the very large-scale, open pit land disturbance, and the other is the in situ process.
There are numerous in situ processes, but as far as land disturbance and forest disruption are concerned, they are similar. They require corridors for the installation of pipelines and power lines to a distributed network of recovery sites. There will be several wells installed from one site and several from another, and several from another beyond that. The overall effect is that linking all those sites to a central collection point causes clearing and construction activity in numerous corridors. My friends in the conservation business would therefore emphasize the forest fragmentation associated with the in situ activity.
Those corridors also require reclamation and restoration as a starting point to the re-establishment of forest diversity.The land area affected by the in situ activity is lower as a percentage, but is probably equivalent in total. In a particular area, only a percentage of the land is affected, but the biggest implication is the fragmentation of the habitat from a wildlife perspective.