Tivo. You can hunt Craigslist or ebay for a Tivo HD (or Series 3 but HD will be cheaper). Then you get a Cablecard from Comcast. Yeah, you have to pay the monthly fee but the GUI is much better than Comcast AND you can pull the shows off Tivo onto your PC/Mac and view it on the road. The Tivo will also play Netflix.
If you are handy w/ Linux, you can upgrade/replace the Tivo drives yourself. If not, you can always get pre-programmed drives on Weaknees or DVRUpgrade.
Sometimes you actually can transfer lifetime w/ a fee, I've done it before. But you almost never do that. I have one box w/ Lifetime and just pay a monthly, reduced rate on the 2nd box. W/ multiple Tivos, you can share shows between boxes, then you don't have to record the same shows in different boxes. Think of it as distributed storage.
The Tivo can also see video servers on the network and play video that way. It's not really DLNA, but it's close.