I ran into this last fall (we were staying in a hotel while between houses) and their free internet had the access page where I had to login and give it the room number about once every 24 hours (sometimes more, sometimes less). Anyway, I setup my PC with a wireless adapter to hook to the Internet, then strung the Tivos (2 of them) to the PC with a switch and used Internet Connection Sharing on the PC to let them connect.
Sounds like the same setup should work for you.
Hitachi 43FDX10B 43" Digital TV, Motorola HD/Comcast Digital cable, Phillips DVD, Sharp VCR, Tivo Series II - 300 hr w/Lifetime Sub and HMO (with its own Comcast box),
Farallon NetLINE USB 10/100 Ethernet Adapter, Comcast Cable Internet, Sony HT-DDW740 Home Theater System, Comcast Digital cable, All operated with a Sony RM-AV3000
Tivo Series II - 60 hr (Stock) w/Lifetime Sub and HMO, Comcast Digital cable, Linksys WUSB11 Ethernet Adapter
I can no longer make backup images available. Requests will be ignored, sorry!