I set the zoom where I can still read the numbers under the unit ( although bombing damage can be hard to read sometimes ) and leave it. I'll scroll around a little but usually click mini map if I have a long ways to go.
Battle calc is nice because you can scroll, it's pretty slow though. Also lists how many units, Hp's etc... I like to see what the units actually are though. Be nice if territory tab would allow you to scroll too.
Can usually see enough of what's going on but I pretty much only play the global map.