You can choose with incomplete information without pretending the missing pieces do not matter.

Deciding without full knowledge is normal; forgetting that you did is where trouble starts. To act at all, the mind tends to smooth over the gaps, so a choice made on three facts and two guesses gets remembered as a choice made on five facts. Holding the uncertainty in view while still moving is uncomfortable and much more useful, because it tells you what to watch for. Confidence and accuracy are not the same quality.

Write down what you did not know when you decided something recently. Keep that note and check it when the missing pieces arrive.