<p>Some ideas:
Get a waist leash. If the puppy’s out of the crate, he’s attached to you by the waist leash. Then he can’t start to go without you.
OR
Set a timer and take him out every 30 minutes, or every 45 or every 60–whatever is about 2/3rds the current “holding it” time. If he goes, great, he can play some more, if he doesn’t, back in the crate for a little longer (another 1/2 the usual time).</p>
<p>It won’t be much longer, if you’re consistent and careful. Really.</p>