score:3
Chinese Yelp is called Dianping -- the Hohhot section is here:
http://www.dianping.com/huhehaote
Search for 咖啡 ("coffee")
Click the button that says 总体评价 ("overall rating") to sort the highest rated shops to the top
Click the first location, a cafe called 艾乐咖啡屋 ("Ai Le Coffee") on 赛罕区万达广场东区底商26-67号(近万达东巷) ("26-27 East Dishang Rd (cross road: East Wanda Rd) inside Saihan Wanda Plaza")
Click the double chevron next to the text 营业时间、餐厅简介、特色等其他信息 ("additional information about this location")
Find that 3 people have indicated this place has Wi-Fi: 分类标签:无线上网 (3) ("Tags: Wireless Internet")
Enjoy!
And if this place doesn't suit your fancy, try another on the list :)