So what does it mean when C fails to move back into the range of the 4th wave?
It does not mean much. The fourth is only a suggestion. Similarly, three wave zig-zag corrections are common, but not guaranteed.
The jump from $4.8 to $7.2 is something else entirely. I'm without internet and am missing all of this fun. My quick assessment however, is that we may see a small upward motion again, before a major downward correction. Bitcoin broke the channel yesterday and seems to be entering again. I'd expect it to soon cross below the channel over the midterm week(s).
My thought is that the abc correction was simply cut short by a new wave of market exuberance.
Maybe, but Elliott already tries to model market exuberance and despair. So trying to explain unexpected Elliott motion using the same terms is circular.
Any thoughts on whether the recent price action leading up to $6.3 is an extension of previous waves, or are we moving into new territory?
The channel I've 'drawn' using the edge of paper on chart since November cuts through the spike on 20 December (wave 3) and again 6 January (wave 5).
After a cursory look, I'm tempted to go back and label everything as a series of corrections.
Do it. Very often an alternate count looks much better after drawing or describing another idea.
It's best to have a number of alternate counts in mind along with what new information would confirm or deny any one of them. If all counts predict the same result, then you can have more confidence in the prediction even if each count is vague.