Save fiat you can pull immediately when the time comes so that you do not panic and end up selling bitcoins or anything digital currency. You do not need to have a back up bitcoin. Do not give yourself that safety net. If you want to really hold bitcoin, then hold every single one you have.
This is one thing I learned over my experience with bitcoin. Back then I would check the price and see how much my money have grown and it would make me excited but then I would get overly disappointed if the price so much as dips for a few dollars.