We run Flexi (both 8.6v2 and 11 Cloud) and just printed a 36 foot bus wrap. Each side print was a 1.8gb file. Flexi chewed through it (printed on the 8.6v2) no problem. Took it about 10 minutes to rip, printed overnight and used all but a few feet of a full roll of vinyl for the 2 sides. That particular RIP computer is nothing too special, older Dell Precision with a single Core 2 Quad processor and 16GB of ram.
One thing I do on huge wraps like this though, I do not open the files with FlexiSign. I copy them directly to the RIP computer and open them directly into Production Manager, set my tile overlaps and whatnot from there.