A high level wizard that is prepared is nearly impossible to defeat. Through their towering caster levels, not to mention the plethora of constructs and simulectrums at their disposal you will almost never fight a wizard alone. Persistant Greater Analyse Dweomers would make that wizard aware of your little anit-magic and would be able to bamf to a safe mid-air distance and use Mordenkainen's Disjunction on your whole party. Or cause a cave-in, create a tonne of Iron ABOVE the anti-magic area to crush you or simply through thousands of arrows at you via telekinesis. (over 1500 to be exact)
Otherwise the good old prismatic wall/sphere makes a wizard impervious to almost anything. Leaving the wizard free to vocally direct his minions (since telepathic contact would fail). My high level Wizards always spend the time to create dozens of Simulectrums. And since these are 60% as strong as the Wizard, and last until destroyed, that bods well for having numerous allies to soften up the adversaries.
Having one or two thought-only spells handy through Silent and Still Spell feats make escaping from a choking grapple easy. The only way you can beat a high level spellcaster (especially Wizard) without using another high level spellcaster is by catching them off guard. Which, I might add, is neigh impossible if the Wizard, is any kind of Wizard at all.