Your work shouldn't be copied from model space into paper space. You create viewports, framed views of model space, which you then insert into paper space. These are views of your model space, not copies of model space, and while the views can be scaled, ie enlarged or reduced, dimensions applied to views in paper space are correct because they measure the model space dimension, not the scaled size in the viewport.
These are the steps: get the view you want in the model space drawing window, invoke "create view", drag the frame around the part of the drawing you want in paper space, give it a name in the dialog box that appears or accept the default name.
Go to paper space, invoke "insert viewport", drag its frame over the paper in that window and nominate the view you want to place from the list. The view you framed in model space will appear in the boxed area you've just framed in paper space.
Select the frame around the view that's appeared, and right-click properties. In the properties box, go to the "viewport" item. You'll see the "scale" parameter there. When you first open it, the scale is unfixed and the ratio is variable, changed by stretching the box around the viewport. Check the "fixed" option and then you can stipulate the scale that you want, that will be printed when you print the sheet. You can type any scale you want there, you aren't restricted to the choices in the drop down list. You can scale up by citing the larger factor on the left of the colon in that box. You'll also see that at the bottom of that properties sheet, you can stipulate whether the box around the view is to be visible or not. If not, clicking in the area of the frame will still select it.
Now, when you dimension that view in paper space (which is a view, not a copy), the dimension will measure the correct, real, unscaled size, not the scaled size that the sheet will print, and the font, size and dimension properties that you apply in paper space are not scaled, and they don't change if you change the scale of the viewport.