High speed down shifting

Hears my question saturday morning i was taking I-80 for a long haul and becouse no one was on the road i was affraid i would look down and see myself doing 90+ so i set the cruise control for a littel under 80. When i started to go up a long hill the van almost imediatly down shifted once normal even though i would have liked it not to yet, then a short time later it down shifts further and the Tach goes to allmost 4.5. That was enough for me i took it out of cruise control and almost imediatly it shifted back to where i would like it. I was able to manually bring it almost back to 80 mph with out it down shifting. My question is how many others think these vans down shift to quickly? Also do you think the cruise control will red line the engine, i mean if i hadent taken it out of cruise control would it have tried to down shift once more?
I remember my grandfathers Chevey Express van where the cruise control would simply shut off if it had to down shift that much. I would think these things would have the brains enough to realize that i dont have to stay at exactly 80 going up a hill and drop down the speed some.

I got 2 of them 99 and 2002 and they downshift little differently.
Having said that just remember you have 185 ponies so at 80 MPH and bit of load I don't think you have much margin of extra power. I discovered that when I was coming back from Mackinaw on I-75. doing 75 MPH it would downshift almost as soon as it went up a slight rise. I had to slow down because it was shifting up and down too much.