Define extended wet conditions. Rain vs large volumes of pooled water? How many days is "extended"?Have you had the Mountain Extremes in extended wet conditions?
Verify the boots are waterproof well ahead of time. Remove the insole and fill them up with water. Look for any leaks or water seeping out. If they are confirmed "good", properly clean and treat the boots before going out. Use a pair of quality gaiters as well. If they are not "good", relegate them to dry weather use and get a new pair.Ok… for the purposes of this discussion, How about 4-5 days of rain, tall grass, creek crossings, and some wet bogs. Some hiking in steep terrain too.