I mentioned previously how I was thinking about a DVR-ish solution to match the new TV. My first thought is to build a baby PC for under $500 and get BeyondTV Link for it. That means I can just stream whatever is on the main DVR into it over the wireless network. To get a free remote, I'd have to buy it today.
BeyondTV has a ton of things going for it, not the least of which is SmartSkip, the function that finds the TV spots, marks them, and allows you to skip them entirely with one button press. Having played with TiVo, that's the thing I still maintain the system has on it. It also records the native off-air HD signals. It's just a really good system, and after almost four years the original computer has long since paid for itself over TiVo or rental boxes.
An alternative I started to consider was to just buy another AppleTV. BeyondTV has an exporting system via RSS that iTunes can use to suck in the shows that it records, and then you can sync those with AppleTV or your iPod or whatever. That's not nearly as seamless, and it doesn't do HD either.
I have to admit that a part of me just gets a kick out of building a new computers, and now that I've been in the Apple world for two years, it has been a long time since I've done that.
Something I use (and BeyondTV might do this) is Tversity. I can pull content off my computer to my TVs using a PS3, Xbox 360, or a modded Xbox1. If I was you, I would test your existing AppleTV in the manner you want to use it in, if it is easy to use I might look into that but if it isn't I would stick with what you are using and add another BTV box.
Also, have you looked into the Logitech Harmony Remotes? I have one and it is a crucial part of me being allowed to have all the toys I do and my wife being able to operate them.
Yep... I have a Harmony remote.
I guess the thing I've got to consider is just how much I'd "need" to watch a show in HD in the bedroom. My guess is not very often, and as such maybe an AppleTV would be a more sensible option up there. That, and it'll have our music library up there.