Can I resize my screen?
If your device have One-Handed Mode option, then you can use that. One handed mode reduces current display to specific size(say 4inch etc). If your device screen is of 5.5 in then using this mode you can easily pull down notifications (you said that your top-right corner is cracked). 

In Mi devices, One hand mode is activated using navigation key combinations(swipe from home key to left or right). You need to activate it from settings before this. 

In Moto devices, swipe from screen's center to left or right bottom corner.

In case if you don't have this option, try this rootless application from  XDA