Calling it a Brair patch strategy is probably not how trump looks at it. He typically doesn’t just bluff. It’s more like a win-win in his eyes. IE: If we get to the Senate, he can go on the offensive. If we don’t, he survives another coup by default and can use it as campaign material
There is a corresponding lose-lose situation for the Dems. If they abort the impeachment they will kill their GOTV for 2020 and probably lose their House majority as well as getting stomped in presidential race. If they go to a long and detailed Senate trial Cocaine Mitch and Graham will see to it that all the Democratic dirty laundry in Ukraine, China and Spygate gets fully exposed to the public, including the low information public. That would be worse for them, imo.