You should check the range with both modules outdoors with no obstructions before wondering about range in more difficult circumstances.
I have had the low power nRF24s (with PCB antenna) working at 110m outdoors and I checked another pair last week at 30m outdoors (I did not need any greater range on that occasion and I did not have space for a very long test).
Assuming they are working OK outdoors the things to consider for indoors (or in/out) include what obstructions are in the way and what other 2.4GHz wireless devices are working in the vicinity.
If there are other 2.4GHz device nearby try changing the channel on your nRF24s.
I will try to test it in an open area with no buildings/wifi around.
A little and the range can be substantially less than outdoors in urban areas.
A lot of buildings may have metal floors, foil backed plasterboard, girders etc.
Beyond that there is not a lot of point in speculating as most buildings are different and there is no substitute for real world tests.
Sure real world tests would be best. But i am looking for a solution that will work in most buildings, and thereby i can't just test it in one building, since it may not work in another building.
But maybe 2.4GHz is just too crowded.
I hope to find a solution with 50-100m indoor range.
I've been looking around for many tech to do this, e.g. Bluetooth 5 (LE), Halow-Wifi, LoRa, Zigbee/Xbee, SigFox, 433MHz/866MHz RF and others!.
But they often lack range, security, sample rate, supported number of connected devices, or is not intended for battery use. Or is just generaly not available on the market!
Suggestions are welcome!