Xfinity Stream does not work on Roku device if not on Xfinity Wifi

Xfinity Stream works great on our Ipads and Iphones no matter where we are or what wifi system we are on.    I have Xfinity wifi and cable at home.   I also have a vacation home where Xfinity is not available so I have local high speed (250 mps) internet provider and DirectTV.   However, I want to watch programs on my Xfinity DVR account.  It works great on my laptop, Ipad and Iphone.   However, when I load the Xfinity Stream Beta channel on a TV with Roku, it states that I have to be connected to a Xfinity wifi?    What good is that.   If I had Xfinity wifi, I would have the cable TV option as well.    Is there anyway to watch Xfinity Stream on my Samsung Smart TV (not one of those that is compatiable with Xfinity Stream as outlined on the Xfinity website) without Xfinity WiFi in the same location?