My page is roughly 500 pixels high x 50,000 pixels wide. If I'm zoomed in close enough that the page height fills the height of the screen, if I drag the horizontal scrollbar all the way to the left or the right, I end up about 50,000 pixels too far left or right of the left/right ends of the drawing. This probably doesn't matter much for a page of a more usual aspect ratio, but it's making it hard to work with this one. It also means that the horizontal movement via scrollbar is very sensitive - three times more than it needs to be.

Is there any way to adjust this, or it it just a consequence of this unusual aspect ratio that I'll have to accept?

Hi pshute.

One solution which hopefully will ease your scrolling to the ends of the page - as in the thread title.
(The procedure is lot quicker to do than to explain!)
See images below.

1. Make a layer - Called "Navigation" (Shift-Ctrl-L)
2. Create a square slightly larger than your page height.
3. Move he square to the "Navigation" layer. (Shift - PageUP)
4. Place the square on the left side of the page - ( Called canvas in Inkscape? ).
5. Duplicate (Ctrl - D) the square and place it on the right side of the page.
6. Hide the "Navigation" layer. (Click on the eye icon to the left of the layer name)
7. Open the XML editor. ( Shift-Ctrl-X ) ( The XML window can be "detached" and moved - if it's in the way - by clicking and dragging the grey area besides the (Shift-Ctrl-X) text. )
8. Find the "Navigation" layer.
9. Click on one of the lines with "rect id"
10. Click the "Zoom to fit selection in window" icon.
11. To go to the other extreme of the page select the other rectangle in the XML editor and repeat step 10.

To move to intermediate places on the canvas other objects could be placed in the layer as well.
____
Click images for larger version

Good Luck
RGDS
Ragnar