Replace on the road, patch when you get home.
There is no substitute for a proper vulcanizing patch and glue. If you do it correctly, the patch will be fused (welded, really) to the tube; you will NOT be able to separate it without tearing the tube; the patch becomes part of the tube.
I've had ROTTEN luck with pre-glued patches. They're OK in an emergency, they'll probably get you home, but take them off, clean with a solvent, and then put a REAL patch on when you get home.

Honestly, I flat about once every two years so it would cost me about $2.50 a year to just toss my old tubes when they puncture, but that would be wasteful.