Deva_Rishi:
I think you'll be fine then ! Now it is just a matter of selection, if your slave router is still visible when far away.
Yes, I will have to create a WiFiConnect() function, which looks for multiple AP with the same ssid, then selects the strongest to connect to.
I thought the ESP-07 has an external antenna connection point ? and a plastic box will hardly hamper your connection.
Yes there is an external connector for an antenna. But there is also a ceramic antenna on board.
If you connect an external antenna thebn a 0 ohm resistor connecting the ceramic antenna must be removed.
I have done so on several other projects and it works good.
I have not said the plastic hampers the signal, but since the box can be placed on one of several sides it can be so oriented that there is no good signal from the AP. The ceramic antenna is parallel to two coordinates and at right angle to the last.