I have racked on the entire yeast cake in the past and if you must do this, you will likely be okay. But I would never do this now that I have learned that doing so would be vastly overpitching.
Your plan is perfect--save one or two cups of the thick yeast slurry from your blond in a sterile vessel, clean your fermenter, and repitch. Some people wouldn't even clean it, they'd just remove all but one or two cups of slurry and rack their beer onto that.
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