Thanks for the responses.

I have read a lot on other sites and it does sound like a clogged screen. Comtemplating the Procopster fix from MVS if it gets to that point, but here is my update:

I hooked up VIDA and cleared everything since there were a million codes from who knows how long ago.
Transmission reengaged after sitting for a few days and worked fine until heated up and then was barely sifting at all, but no dash codes, and nothing in VIDA. I am new to VIDA so I don't know if I exhausted the diagnostics in there. (I could not seem to activate any modules. Maybe you need the subscription for that?)

For those who don't know about the clogged-screen problem: Particles in the fluid fall off the filter to the bottom allowing the trans to work until the particles again clog up the screen and kill the fluid pressure.

A couple ways to verify that this is the problem:
Pull the return hose from rad and check flow. If it is a trickle, chances are good that’s the problem
Listen for a whine from the trans, which is the pump getting starved for fluid. In my case, this is tough to hear because the PS pump has been on the way out and making a racket for a while.
From what I read, the clogged filter problem does NOT throw a code

There is a way to address this by drilling a hole in the bell housing, inserting a skewer into the filter and puncturing the screen. See Matthew’s Site for details. Sounds a little savage, but it seems to get the car back on the road for a while, maybe longer, but only if this is the problem. Also, as Astro points out, I know this might not be the ONLY problem, but it did shift great before this. Also need to add an inline filter if I go that route.

So my plan is this:

Test the pressure by pulling the hose
Flush the fluid (of course). But I doubt this will suffice
If none of this works, consider the Procopster band-aid

Unless there is anything else I can do in VIDA?

thanks!