Modify duration of After Effects graphics in Premiere Pro CC?

I am quite new to Adobe Premiere (came from Cyberlink PowerDirector).

I downloaded an lower third template that was created in After Effects and exported to an "Essential Graphics" element that I use in my Premiere projects.  However, there doesn't appear to be any way to extend the duration of this clip.

So I actually have a couple of questions:

1. Is there a way to extend the duration of an Essential Graphic template that was created in After Effects?
2. If I were to purchase After Effects and create my own lower third, can I create them in such a way that the duration can be determined within Premiere Pro?

Basically, I'd like some help determining my options. The lower thirds in my videos need to have easily adjustable durations (preferably using the same click/drag motion in a sequence timeline as other clips). If that cannot be done with an After Effects graphic, do I need to create the lower third in Premiere and not AE instead?

Thank you!

EDIT: I should specify that I am aware of the ability to change duration by modifying the playback speed of a clip, but that is not what I'm looking for.