While Codreanu's survival could be by accident, one can reasonably assume that it would be the result of a different policy and attitude by the royal government.
In which case, however, the what-if is not about Codreanu and his possible survival and policies if he survives; it's about the rest of the political forces in the country, why and how they changed their minds, and what they'd do once they came to agree with the Legion's ultra-nationalist stances.
Maybe I didn't phrase it clearly enough. The Second Vienna Award came two months after the Soviet annexation of Bessarabia. These Legionary "old guard" elements wanted to resist the Vienna Dictate so much, that they were even willing to ally with the USSR after it had already taken Bessarabia (if necessary).
So I suspect Codreanu's answer in this
hypothetical would be "sounds good, when do we start?". After all the "price" called Bessarabia and Bukovina has already been "paid" anyway.
Sorry, I doubt it could work, if things work out in the same order as in OTL. That's exactly because, if Codreanu had been alive, he would have done anything, up to and including more political assassinations, to prevent the handing over of Bessarabia and Bukovina. Especially to the Soviets.
He could hardly then turn around and tell his base that it's now up to the Soviets: since they have already taken what they wanted, they should now ally with Romania and defend it from Germany.
And, if he did, it's not a given that the Soviets would run such a risk anway; they feared Germany more than they coveted the advantages to be gained.
Could you name, by the way, a couple of those "old guards"? They're not Sima and his men, they are not the inner circle of Codreanu, who are they?