The yellow pcb with the 328p & rfm95w on it, its a special design from yourself? Something like this (an arduino like design but reduced to the minimum necessary) and a bigger atmega (a 1284p for example) would be great to handle more complex stuff (lmic+gps library = not much space left) - thought about a moteino but they are not available in europe and the shipping from them is way off the pricescala.
Btw. love your pcbs - using them for our gateways, would be really cool if there would be a “standard” pcb from you for nodes.