I don't know the legal intricacies of this situation. I believe it is unprecedented and new legal arguments and theories will appear.
U.S. Grant was arrested for repeat offenses of speeding in his horse and buggy in DC but was not jailed. He had to walk back to the WH.
https://www.davemanuel.com/2021/01/11/us-president-arrested/
I do not like to think of Trump in a NYC jail without security including a food taster.
So what's the plan?
They are backed into a corner, no way out. The deep state is not having Trump arrested because they think it will hurt him politically, or to convict him so he can't run in the next election, or perp walk him, or any of the other hundreds of theories I've read over the past couple of days. Get real. They want to take him into custody to separate him from his secret service detail so they can Epstein him. They are desperate.