definitely. growth in starters seems to be capped by starter volume (see "Yeast"). Make sure you practice sanitary handling when you're transferring the slurry, though. The main issue here would be the danger of contamination.
Alternatively, given that the viability of the saved slurry will drop fairly quickly if you just refrigerate it, why not wash + reuse (use a starter: again, quality AND quantity of yeast are important) the yeast cake remaining after the brew?