There's the answer to your question, right there. Get an intermediate mix going, with a minimal up-potting, and wait for the final mix to come in.
Roll about 1/2 cup per 5 gallons of Dr Earth into that, along with a Tbsp of either dolomitic lime or ground eggshells.
These days, I really keep it simple.
Got a 5 gal bucket of your exact mix ready to go for the little bacctums,, I'm tempted to add 1/2-3/4 part organic Kellogg or organic Miracle grow container soil to this mix, would that help or hurt..?