<p>Let's say I win this huge award that can drastically change everything 1-2 weeks before decision letters are out. Would it be too late to affect decisions?</p>
<p>Basically, no downside in telling the college.</p>
<p>If you were already accepted – won’t hurt.
If you were already rejected – probably won’t help, but can’t hurt – and who knows.
If you were Wait-listed or no decision had been made – could help.</p>
<p>Overall – no downside. Hope you get this award (unless this was a hypothetical, in which case, I hope you get a hypothetical award).</p>