CrossRoads:
The device does support two addresses. There appears to be a solder jumper to let you select whether it is tied high or low. It's the three squares on the bottom of the board.
Right - I made the wrong assumption based on the fact they stated "only one"... the web page does state
This board/chip uses I2C 7-bit addresses 0x39, 0x29, 0x49, selectable with jumpers.
--> so just set 2 different addresses and you should be good to go (probably need to worry about I2C pullup resistors)