In assessing McConnell's words and his resolve there are two factors to consider.
The first is, obviously, party loyalty and the strengthy of Trump's support. The idea that even anti-Trump senators would vote to commit political suicide has always been a fantasy.
The second factor is loyalty to the Senate as an institution. The Senate is faced not just with an out of control partisan political theater in the Dem controlled House. It is also faced with an aggressively Imperialist House that is, in effect, attempting to dictate to the Senate. The outrageous conduct of the House Dems asserts that the House is the leading half of Legislative Branch and that the Senate must conduct a trial if the House instructs it to do so. McConnell is not about to lay down for that. The Senate, as we are told, is steeped in tradition, and senators are unlikely to allow the Pelosis and Schiffs of Washington to relegate them to a ceremonial role.
Thus, McConnell's words, brief though they were, throw down a gauntlet by raising the issue of due process in no uncertain terms--McConnell: House impeachment resolution 'falls way short':
“They have denied President Trump basic due process and are cutting his counsel out of the process in an unprecedented way. House Democrats' new resolution does not change any of that,” McConnell said.
“The draft resolution that has been released does nothing of the sort. It falls way short, way short,” he added.
By slamming the lack of basic fairness, of due process--a Constitutional standard--McConnell is, I believe, drawing a clear line. He is warning that the Senate will not be a party to a proceeding that makes a mockery of the Constitution. No doubt he and others in the Senate are working out strategy, now that their position has been decided upon. Of course he will be working within Senate rules and will need to tailor his strategy to that framework.
Another thing to keep in mind is the state of polling. There's a new poll out should give nervous Dems even more pause to reconsider Impeachment--and even the ongoing Impeachment Theater. The news for Dems gets worse the deeper you dig, but even allowing for the widespread misunderstanding of the issues the results of the poor are very bad for the Dems. When you consider that bringing all this to a vote could lead to more awareness of what's behind it all, the news should be quite disturbing:
Impeachment Poll to Democrats: Put Up or Shut Up
Addendum: Here's a good article today that addresses a major Constitutional issue surrounding Impeachment Theater: A factually Weak Impeachment Will Alter The Nature Of Our Government. It's not revelatory, but it's very well thought out.