I only take one set of camo, but during the late fall and winter months I dress in layers so technically I carry more than one set of clothes. I always take extra socks and underwear though.
I dont bother with a fire since it just spreads scent around, and requires a bit more work to get going and to maintain....although I have built a fire or two on occassion to dry out clothes. To be honest I don't think the fire or smoke smell alarms the wildlife too much. I think they are spooked quite a bit more by human odor, but that is just an opinion.
For water I just fill up a water bladder for the walk in, and stop periodically to purify the stream water and refill. Iodine, sweet water, and the purifying water pumps all work just fine. If it is strictly for drinking water I will add some Gatorade mix, Emergen-C, or even Kool-Aid mix just for some flavor. Once I get into camp I have a water jug that I fill for cooking. Cooking involves boiling water on a backpacking stove and adding whatever dehydrated or pre made foods we decided to bring.