Use a Viewport.
Once you've established a view in Modelspace, make it a Named View.
(right-click on any of the Standard View icons)
In Paperspace, use Insert / Viewport.
Click and pull out your VP window and choose your Named View.
In Properties for the Viewport you can click on the "Fixed" box
and set a Scale; choose from list or type in your own.
That's one way to get what you want.
Designer, Deluxe, (Professional, Expert, Basic), Platinum
Windows 10 Pro (1903), 64-bit