I agree with you completely- thats their only play now. But the testimony has been so devastating to their narrative that its possible the House will not pass it.
That would require some sane Democrats, which is a tall order.
But to vote for this sham now is also a pretty sure way to end a political career.
Behind door #3 is the escape door. “The impeachment is justified but is so divisive and is tearing at the fabric of our democracy, (Republic), so we will opt to vote for censure and let the voters decide in 2020”.