Most of my 1080p files run around 4-7GB depending on length of the movie, and my 720p movies go from 2-4GB.
I personally don't use the CQ function as it often varies wildly in file size and sometimes sends bitrates out of control. I use 2 pass variable bitrate encoding with average bitrates of 4800 for 1080p and 2800 for 720p. This keeps file sizes in manageable sizes and looks fantastic on my 55" Samsung TV.
This method ends up being roughly 1.9GB per hour on 720p, and 2.7GB per hour in 1080p. I also keep 2 audio tracks, one as AAC CoreAudio Dolby Pro Logic II 192kbps, and a second Audio track of AC3 True 6 channel surround at 448 kbps. I know that the Dolby can be reduced to 160 with a negligible loss of quality, but I can tell a bit of a difference when I turn the volume up, primarily in the bass. Also, the extra 32kbps means an extra 9 MB on the file size for a 2 hour movie so big whoopdiedoo.