Hi, and thanks!
I'm not sure about bars round the stadium. The metro stations there are for the university, but it's just a campus I think, not like our Unis...I doubt there's any there knowing France.
You'd definitely be better off staying in the city to watch it on TV, there's bars in the Old Town (like the Oz bar) and the centre which will show it, and the Irish pubs on Solferino. When it's a Lille match especially, a lot of places dust their tellies off and make an effort too, so it should be on in enough places. Ask people in the street where you can watch LOSC (call it "losk" not Lille) and they'll know.
The metro to the ground and back is like 30 mins tops, so you'd be back before kick off anyway.
Yeah you can buy tickets on the gate for the home end if there are any, but I guess you'd have to be French or do a good impression... again, not sure.
I've asked an ST holder mate what he thinks it will be like for us in the home end, getting in, trouble etc - waiting for him to get back to me on facebook.