I never have heard about a wifi module which can connect to two access point at the same time. But I have used esp8266 module , that would be useful for your application since it is very cheap and easy to use. This SOC can act as both access point and station mode at the same time. If it is in dual mode (station and ap) you can connect many devices to this and it can be get connected to one Ap as well. Other wise you need to interconnect your routers and do the port forwarding to your device's ip address.