Maybe. Maybe not. So far, I think the GOP has clearly expressed that they would rather not, and therefore haven't ruled it out. But, even if a GOP senator supposedly "ruled it out," the word of 15 senators makes it happen. I can hear something like "In light of the rpesent circumstances, which we did not anticipate, we are calling for cloture LOUD AND CLEAR."
Surrender is the final act, and in Estrada's case, is signaled when the GOP pulls the matter off the floor, but not before.
Unless they go 24/7 after the a failing cloture vote they will be pulling from the floor.