All the GOP congresscritters - Graham, Hurd, HowdyGowdy - say that Mueller’s probe is not affected by the memo. It must and will go on, they say. In short, he can sleep very soundly tonight. the GOP still has his back.
They are probably correct as 1) here really is no direct prosecutable evidence of a crime, rather many are inferred, direct evidence may be in the underlying non-public documents, but not in the memo itself. 2) that memo is the first of a number of them.
As for Mueller and his probe, they seems to be going rapidly nowhere, so stopping them because of that memo would just beg the question. The only thing the memo does is put the whole Flynn, Page, Popodopulous indictments in grave doubt.
Just wait and see, this is a very slow process. The IG report will have more.