How much video fits on a standard DVD is not really measured in minutes, it is measured in gigabytes. If your video is 4.7 GB by the time you get done adding chapters etc, it is not going to fit. If you reduce the video resolution you can fit more time into the same 4.7 GB because the file will be smaller. If you really need a large high resolution file that is more than 4.7 GB total, look at a dual layer DVD burner, and buy the dual layer discs.
File compression is really just another way of reducing video quality. Just reduce it at the source and don't worry about compression.
The maximum time for a movie on DVD is approx 2 hours - the '90 mins' is only a suggested playing time in the Burn menu.
If the movie is too long to fit on a DVD MEP will prompt you to adjust the bitrate to get it to fit into the allowed space - MEP can do this automatically if you click the Adapt bitrate option.
If the movie is less than 2 hours long you can increase the quality by increasing the video bitrate in the dialog shown in this image - if you adjust it too high and the movie will not fit on to the DVD then MEP will again prompt you.