Resize timeline to clip

First all, apologies for the nooby question, but I'm having troubles with something, which should be pretty easy to accomplish, in Resolve 14.

I have a very short and lonely clip in my timeline and I've cropped it to fit someone's creepy face: how can I resize the entire timeline to that cropped section so that when I deliver the project the output size is correct?

Also, is there a way to crop to non-square shape?

it's easier if you approach this in reverse. Setup your timeline resolution to desired dimensions in Project Manager and then scale the clip up and move it in XY on the timeline until you reach the cropping you like.

You can crop non square by using a window in the Color Page. Once you have the crop you like you can crush the RGB values outside of the window to 0,0,0. Alternately, you can Add Alpha Output by right clicking the Node view and connect the node with the window to the Alpha Output.

Setup your timeline resolution to desired dimensions in Project Manager

Is there an easy way to obtain that info from the crop or should I do the overly complicated math all by myself?

No really, I can follow your instruction and that's fine, but seems a bit overly complicated for such a simple task... and I'm looking at this with the perspective I might want to do this again.
I hoped for a command of some sort like "resize to clip"...