Clear out of the house for a few days. Let them come in and sand the hardwood and put a few coats of Bona Traffic on it. This is a commercial grade water based urethane. You shouldn't have nearly the problem with lingering fumes that you have with oil based products. You could also just install laminate over the existing wood. It won't hurt the hardwood underneath and there are no fumes at all to worry about. Ceramic is probably going to cost you a fortune considering you have a tongue and groove floor to deal with as a base.
sounds to me as if tile would be your best bet, considering your allergies.
however, cork planks might work too?
softer, comfortable and warm in the winter. not too sure what gassing it would do though.
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