First off are your feet wet form the boots weeping(meaning outside moisture getting in) or is it due to your feet sweating? If the later the best goretex boots money can buy will never keep your feet dry alone! If your feet sweat buy some polyproplene sock liners(moisture wicking)and top them with good quality merino wool socks...both will go a long way in adding pleasure/warmth to your day. Anything cotton will end your day in hurry when they become damp, so x these from your hunting attire!

For boots I agree Gortex lined boots are the way to go, this will stop moisture entering from the outside. The amount of insulation is really dependant on use and your feet. If you have sweaty feet it is counter productive to go with a higher gram thinsulate boot for walking at least. I am in this group and have found the combination of a good quality gortex boot and the socks I mentioned coupled witha 600 - 800 gram of thinsulateboot is sufficent and in fact warmer. If you stand hunt then changing to a heavier boot or buying some Artic Sheild Boot Blankets is a good idea for when on stand. Also when buying boots make sure you have wiggle room & don't tie them up tight, loosen the laces when you plan to sit for an extended period.