save the champagne yeast for later. wine yeasts can't digest maltose so that will be left behind. champagne yeast is also a "killer yeast", it will kill any sacc in there.
as suggested above: get a high gravity yeast (wlp090, wpl099, 1056, some of wyeast's belgian strains, etc), make a starter, and pitch that at high krausen
Originally Posted by FluffyMuffins
I won't be able to get out to the store till Saturday. Will that be too late?
sooner is better, but you should be fine.