I found that by adjusting the size in the Timescale options, I can view up to 10 weeks while still showing the available time per day (in a readable font size).

I didn't show 2 screenshots. It was 1 screenshot where the Gant chart was the main view, and the Resource Usage was the detailed view. But when I tried the other way round, I can indeed collapse the resources. Seems like you can't collapse items in the details view.