Completely disagree with this first comment. A "Universal Playoff" is a perfectly acceptable option. I thought we were trying to address the problem of unwanted byes.
A "Winner's Tournament" is also a good option. And if we go that route, then I'm OK with your second set of comments. It should be noted, though, that if you brought all 5 teams to a central site, you'd almost certainly play Thursday through Saturday. I suppose Friday through Sunday could be a viable alternative.
Another possibility: Playing the #4 vs. #5 game on Tuesday might be more fair in terms of the rest factor. Most likely you'd treat this as a Play-In Game, hosted by the #4 seed. IIRC, the Men's CCHA playoffs used a play-in round for a few seasons.
The Women's WCHA also had a Final Five for a short while. At the beginning, in 2000 & 2001, the Original 7 teams all went to a neutral site. But in 2002, 2003 & 2004, the league went with a 5 team format -- very similar to what shelfit describes. North Dakota joined in time for the 2005 tourney. That year all 8 teams went to a central site, which happened to be Ridder. Starting in 2006, the first round match-ups went to campus sites, followed by the four team Final Face-Off. Not sure if the term Final Face-Off was used immediately. But IIRC it's been that way ever since.
With North Dakota now gone, you can certainly make a case for a return to the Final Five format.