...but WordPress does a dynamic page generation. I don't know how to find out what that size is. Can anyone assist?
If you only want/need to find the size of a few pages, a default install of the Opera browser might help as it has a 'progress bar', which you can position via Tools \ Appearance \ Toolbars \ Progress Bar
It shows Document Size, Image Count, and 'Download Speed'
Note: this info disappears once the page is fully downloaded... and would probably be easier to read on a slow dial-up connection