Firstly, RUTX11 and RUTXR1 are almost similar to the performance wise as they both have same CAT6 Supportivity, CPU and Ethernet speed but they are not the same completely.
Secondly until the Antennas Meet the specific standard to support RUTX11 device and are capable to connect to the network, cable size does not matter.
Coming to the Operating Temperature of RUTX11 it has a range of -40 °C to 75 °C. Hence 5-to-45-degree celsius does not concern the performance of the device.
Again, as I have mentioned about the Performance of both the devices, based on the application both of these devices can be used. Temperature also does not concern as the Operating temperature range is same as RUTX11. Again, until the Antennas Meet the specific standard to support RUTXR1 device and are capable to connect to the network, cable size does not matter.
Note: RUXR1 might require more space in terms of length compared to the RUTX11.
RUTX50 is also a good option if you looking to upgrade as it also support 4G networks and in future can be used for 5G networks
Please refer to the link to know more: https://teltonika-networks.com/product/rutx50/