There was this report of using a Wifli Etap with 50/34 and 11-36 cassette:
Technical FAQ: Frame sizing, wide gearing for road bikes | VeloNews.com Scroll down...

No evidence of Wolf type extension needed. With etap brifters and RD/FD with batteries and charger now
available for ~$1200, adding a cassette for $60-100 more and a R side compact (I suspect 52-36 would
work as well) would mean a perhaps $1500 conversion.