No, it's not solved, because the Vancian caster is still driving everyone to a [small number of] encounter
per day and then forcing a rest so that he can survive the expected wandering monsters.
The problem you're trying to solve is "Vancian caster resource expenditure forcing a 15-minute adventuring day," and now you've just forced it to happen from the other side: instead of running themselves dry quickly and then forcing a rest, they run themselves to minimum required to safely rest and then force a rest.
He is only driving it if the DM and the rest of the party allow him to do so. In the games I play in the rest of the party would say suck it up we are not stopping after just 15 minutes.
Pacing is part of the DMs job in his tool chest he has wandering monsters and other tools to control the pace of a game.
Maybe I have been lucky and I play with players and DMs who realize that the whole world does not stop just because the PCs do.
Let them nova and keep the game running and eventually they will either learn to stop doing it or they will still nova and go on using crossbows and throwing vials of acid.