I'm going to be in a position shortly where I need to provide a router to run a small wireless network, local networked file storage and internet access to a small group (10 people or so). I've already got an Asus RTN16, which I'd like to use for its built in network storage capability but I'm not averse to buying new kit to supplement or replace as required. My big sticking point is that the internet I'll have to connect to will be an infrastructure network with an HTTP login portal before proper internet access is provided. I know this is a terrible situation, but I've got a bat's chance in Hell of getting a network admin to even give me the time of day.
My current plan is to use a raspberry pi with a wifi dongle to connect to this WAN and sort out wifi login via VNC, using a real browser on it. In that situation, the raspberry pi's wired connection would presumably have to be on the WAN of the router with an manually assigned IP (how should I choose this?) and so should be reachable from the LAN side of my router to fix the WiFi login as required. Routing between the two interfaces on the pi shouldn't pose any problems, and all traffic should look like it's come from the raspberry pi with its DHCP-acquired IP on the WiFi side.
Does that make any sense, will it work and am I missing a more obvious/reliable solution?