I think the provisional government would face issues as the left-wing anti-war agitators gain strength.
As it was the Provisional government didn't lose that much territory: Just Poland, Courland, Lithuania, and Grodno. Sure, the military government basically declared the agreement null and void, but those lines still set the basis for the post-war boundaries. A Russia impacted by the instability of continuing to prosecute the war (rather than taking a month off before the militarists took charge) may have lost even more territory.