How does extradition take place between states?

You can't hide in states. IMO.

I think it happens for maybe a day or so, but has always been a procedural thing.

I've been wondering myself!

If he prevents a court decision from being carried out, but the extradition can be contested to delay it. Once that's decided I think a Gov. Is at risk legally if he prevents it, but legal minds surely know for sure.

but (as with other arrests), the lawfulness can be contested by habeas corpus (unless the writ be suspended for insurrection or similar threat to public safety)

I expect refusal to honor a lawful extradition request would produce a suit and subsequent order to honor it, but the lawfulness could be contested by the detainee with a habeas action; in the current context, suspension of the habeas right is unlikely to be considered or upheld

from ILL to Wisc? He was eventually extradicted to WI, but it took longer than usual.

The few times that I have seen it 'work' on the news reports was when an execution state like Texas wanted to extradite someone from a state with no death penalty. Then the original state might try to hold onto the person or try to work out a plea agreement with no death penalty if the original prosecutor was so inclined.

Best case scenario is someone is picked up about 1 block away from the white house or at the airport before boarding a plane.

Rumor has it that there are more than a dozen sealed NY indictments waiting for him. I hope Mueller's crew were able to seal some as well before Bill Barr killed the investigation (there could be at least one with several counts from the Cohen documents with Individual A).