Water - go to your local camping store, and pick up a 5 gallon water bottle. This way, you know the water is clean and safe.
Critters, not good. Maybe you should look into having someone up to clean the cabin before you use it. Animal droppings are unhealthy for everyone, healthy or CF... and I have to imagine it's worse for babies.
Nebulizer. We power Jeremy's either with a power inverter connected to the car (350 watts will power the neb machine, 700 watts will power the vest), or using a portable power supply. The power supply works great (it won't do the vest/neb at the same time, so we run one off the car, the other off the power supply), and we can get about two vest treatments before it needs recharging (which can be done from the car). We're also thinking about getting a Pari Trek for camping - especially since we want to go backpacking.
350 watt power inverter <a target=new class=ftalternatingbarlinklarge href="http://www.walmart.com/catalog/product.gsp?product_id=1818511
">http://www.walmart.com/catalog/product.gsp?product_id=1818511
</a>700 watt power inverter <a target=new class=ftalternatingbarlinklarge href="http://www.walmart.com/catalog/product.gsp?product_id=1818512
">http://www.walmart.com/catalog/product.gsp?product_id=1818512
</a>Power Supply <a target=new class=ftalternatingbarlinklarge href="http://www.campingworld.com/browse/skus/index.cfm?skunum=26434&src=SRQB
">http://www.campingworld.com/browse/skus/index.cfm?skunum=26434&src=SRQB
</a>Pari Trek <a target=new class=ftalternatingbarlinklarge href="http://www.pari.com/products/pariTREK.html
">http://www.pari.com/products/pariTREK.html
</a>
We're going on a sailing trip this weekend, so we'll be bringing the power supply with us to do the neb, and I'll do manual PT instead of the vest.
Cleaning neb parts. We just boil some water on the camping stove, and pour it over the neb parts.
Campfires. Jeremy says he feels a bit "tighter" in the chest after we have campfires, and he's usually more congested the next day. Try to stay away from the smoke.