Seems the general consensus is wait until the end of the season and make sure the new gaffer isn't in any way associated with this car crash of a season.
Personally I'd get someone in a.s.a.p as we have a two month head start on the two other relegated teams as we all know we're down, Bernstein has said as much and I imagine he'll be one of the key recruiters of the next guy.
Don't think there's a moment to waste, if only so he can see how terrible some of these players are and boot them out of the exit door in the summer.