Wine can be used as the liquid in your soap, but all of the alcohol content will need to evaporate before it can really be used. It will definitely need to be boiled for a while on your stove to accomplish this, and yes, I'd freeze it to the slushy stage right before SLOWLY adding your lye to it. It will STINK to high heaven when you're dissolving your lye in it, but that does dissipate after the soap is poured into your mold, and even more so while the soap cures. As far as champagne goes, you will need to let your bottle sit out and open for 3 or 4 days, making it very flat. Then, boil away, freeze it to a slush, and proceed.