I think an EF4 is all but guaranteed. The question is whether it'll go to 5, really. Some part of me doubts it -- I was almost certain the Bassfield tornado would have earned that rating, but the NWS seems extremely particular about what they consider EF5 damage. Not a criticism, mind you, they know what they're doing, but I've been surprised at numerous storms that seemed to be a lock for EF5 not making the grade.
Hopefully a revision will be made at some point to include more damage parameters, especially for those that happen over open countryside.