Time Capsule WiFi Range

Am currently still using a first generation 500gb time capsule, but in our new house the wifi coverage it provides is pretty hopeless. Main problem is that no wifi signal reaches the tv, so currently I can't stream any movies from my iMac to the tv (and to offset the obvious suggestion, the electrical outlets mean that moving the tv isn't an option!). So, I'm looking at getting a new time capsule, partly for the increased storage, but mainly because everything I read suggests it will provide a greater wifi range. My question is can anyone give me an idea of how much greater the range is? At the moment, the signal drops about 5m before you reach the tv - will the jump from 1st gen to 4th gen make up this difference? Thanks in advance!