@Eli1,

Technically Yes, Realistically - Maybe

Setting up a nano router is supposed to be able to take care of situations like this, but it really often comes down to the unique network situation. I have had success with similar setups at some hotels, and complete failures at other locations. I would recommend looking at the Xfinity forums to see if anyone has been able to achieve the functionality. It really is dependent on whether or not the login, when done on a PC is forwarded to the Nano Router.

Now that I am thinking about it, if the nano router has MAC cloning you may be able to configure the network this way

  @Eli1,

Since this popped back into my notifications:

I do remember being able to use a travel router for a network at a timeshare, and it simply forwarded the client portal through the router. It worked for us to stream music to a google home and the new chromecast; but we did run into a few problems that probably could have been fixed with a correct configuration when we were trying to stream a movie or maintain a connection over a longer period of time, almost as if an IP wasn't being refreshed properly. 

If you ended up trying to use a nano router for this, were you able to get it working?