I dont think there would be a delay if Grassley refused to entertain any accusations without supporting evidence. He could then blame Feinstein for holding on to the information so long that it would be impossible to evaluate any evidence, had their been any. Those are both good reasons to proceed to a vote, both in the committee and the full Senate.
Yes he blames Feinstein already but the fact that it is her fault is not going to make any of the news shows.