I have been looking for this wine and can't find anywhere to buy from. Any ideas would be appreciated.
From what I can see on the TTB's COLA site, Latitude Wines seems to be the most active importer of Pascal Lachaux. You could contact them or the other importers listed to see if they can help. Go here: https://www.ttbonline.gov/colasonline/publicSearchColasBasic.do and put in the date range (go back a few years) and just type Pascal Lachaux for Product Name. You don't have to enter any other info into the other fields.
According to Wine Searcher the most recent Pascal Lachaux wine available at retail is from 2013. I noticed some articles about his sons taking over the winery, and that one of his sons making a Pinot Fin under the Arnoux-Lachaux label, which is imported into the US by David Bowler. Perhaps the fruit from Cuvee Bonheur is now going into that wine?