I would think that the bootbag that they have given away outside the stadium would be okay. My wife and I used to bring a canvas bag to the spring and fall games with a blanket in it along with spare ponchos and sharpies. Sounds like I'll have to wear the blanket from now on. From time to time I would bring my camera and camera bag into the stadium - that's an obvious no-go now.
and apparently I'm not allowed to bring my cooler in anymore either