doesn't help you now, but I'll crush 2lbs of 2-row, mash, sparge, and then bag and freeze the wort.
when i need a starter: thaw, put in small pot, boil 10-15 minutes to sanitize, then I pitch that.
I did the math to produce a wort that was right about 1.040 for freezing.
if you have leftover wort from a real batch you can always freeze that too.