If the House votes for President, it is by State Delegation. The Republicans are majority on 26 delegations. PA is tied. MI would be tied except for Justin Amash.
"Immediately" is not defined. I can see Nazi Pelousy delaying any vote so as to give the Dems time to strongarm the Repubs into voting for the Dem candidate.
I apologize for being so cynical, but I've just seen way too much crap from the Dems these past three years, and this year the will pull out all the stops and go completely rabid....