How do I change a clip's speed to fit in within a timeframe?

tl;dr: How do I change a clip's speed to fit within a specific set of time without losing a significant portion of the clip? (see explanation below for what I mean by the last part)

I know how to change clip speed by percentage (by right clicking the clip and selecting change clip speed), as well as how to adjust it using retime controls. For a lot of my work, I want to take relatively long clip and squish it all down into a small chunk (sort of like a lazy montage). Retime controls are half decent at this, as I can easily just drag the slider into the size (by time) of clip I want. However, using retime does not squish the whole clip: the end is always cut short.

Open retime controls and grab the edge of the upper bar. This way you can stretch the entire clip to the desired length

Open retime controls and grab the edge of the upper bar. This way you can stretch the entire clip to the desired length

As I said, doing this will actually cut out a significant portion of the clip (more than what would be expected from just skipping frames due to the speed up). So this does not solve my problem