Hey I have to play the Marriage of Figarro excerpt and there are repeated 16 note that go as fast as the Speed of light, literally! Should I double tongue or should I single tongue?

Hi! I noticed no one replied to your post. I assume that you've already come to a conclusion?
I know some people who single tongue this excerpt. Yes, sure, I'm jealous. But I have a slow tongue. I double tongue it, and it sounds the same...but it took a LOT of practice to get it there. If you can single tongue at 144, DO IT! If not, try really hard not to sound like a helicopter.

Yes, doubletonguing is the only way I've ever been able to get there.

While I agree on the double tonguing (it's what I personally do), I would start at a slower tempo and lightly legato tongue those notes and work up to the speed you need. As you speed up, work to maintain a light legato tongue- the lightness will overcome the legato giving you a beautiful note length and tongue endurance. This may be impractical if you need to get it done sooner than later but the benefits outweigh simply learning to use your double tongue.