So if your college's network admins are sophisticated, they could detect what you're doing. Please note, though, that algorithms and probably products do exist to try to discover if NAT is running on a given device, based on the fingerprints of the traffic going to/from the suspected NAT's public IP address. The fact that you would have all your traffic going through NAT should obscure, at least from the casual observer, the fact that the traffic is actually coming from multiple client devices. You could have that same box also have a private LAN or AP-mode WLAN port that doesn't require authentication, and connect your non-802.1X-capable devices to that. It's definitely possible to set up a device to act as a NAT gateway, and have its WAN/public Ethernet port run an 802.1X supplicant (or, if its WAN/public port is Wi-Fi in client STA mode, have that port run a WPA2-Enterprise supplicant).
