Now and again, folks are here talking about difficulties with their Legacy CAB2 communicating with the base. I've experienced that myself in a large basement layout with obstructions. One option that might be worth a look is a booster amplifier.
I have not used this for the Legacy system, however I do have a problem with my home WiFi signal. My house is around 85 feet long, and the router is at one end on the second floor. Reception at the other end of the house is spotty, even with a 15dB corner antenna beaming the signal in that direction. I picked up this 2W 2.4ghz 2-way Booster, and the difference was remarkable! I now have plenty of signal strength at the far end of the house, and even out onto the deck in back! I suspect this would do similar good things for the Legacy signal.