well they all suffer that fate with the old receiver, it just depends if the right RF signals are present. Often various household stuff uses the 433mhz frequency. For instance i have a wireless thermostat for the heating that uses it.
When i parked it directly in front of the house, it certainly drained the battery within a couple days, enough that i went and bought a solar panel to keep the battery topped up. However parking to the side of the house for several weeks without the solar panel attached seems to have no drain issues. But clearly refitting the antenna i'm sure will make it much worse
I'm still slightly wary about using the remote, because i dont want it superlocking itself and leaving me stranded. I've not quite managed to figure out what makes it superlock, so for now i've been locking with the key and unlocking with the remote. I will at some point disconnect the superlocking wires within the locks to ensure it cant do that!