No, we'd have not seen 55% of Republicans vote for impeachment. Like I said, you discount the fact that views on whether impeachment is necessary to terminate one week of a Presidency are absolutely a factor in play and highly important. For whatever reason (personal morals, fears of losing their voters, etc) most of them decided it was not.
Yeah, politicians are hypocrites. The sun is also orange, and rain comes from clouds. I mean not to insult, but more offer a jaded agreement that politics and integrity rarely demand the same course of action.
It's not broken, but the rift within it has certainly widened by a lot. There are the moderates (Cheney) and the diehards (Hawley, Cruz). The moderates will generally break towards party lines in the future, but will act independently to get results. The diehards will always break towards the views of party whips and kingmakers. For the next few days Trump will occupy that position (I postulate he'll flee the country on the 20th, but we'll see what happens...bit of a digression there).
If I could hazard a guess, and ironically enough this does somewhat line up with your snap poll, I'd say just over half of Republicans will fall into the moderate camp. Nuances that affected the impeachment vote aside, I'd bet you $5 that we see this camp generally prioritize bipartisan solutions rather than party line politics.
That leaves what I'll estimate to be about 35% of Republicans in the Trump camp. They may not all support the attack (this grouping encompasses a few million people at least, and even a tiny radical percentage of million is more than the hundreds we saw last week), and I would bet another $5 that within a year most of these people will abandon the man and try to return to the moderate center.
The GOP is currently evaluating its situation. Trump dealt them a potentially fatal blow, losing them both Houses and the Oval Office for the first time in decades IIRC. The vocal minority will try to posture and preen for as long as it can, but they will never represent a majority view within the party when it comes to supporting a single man over the rule of law in this country.
(This is somewhat of a rambling diatribe...I pulled a very long day at the firm and need to go to bed. lol)