Another scenario that might have happened had Nicholas tried to keep the throne by force is that he might have ended up dying sooner. Look what happened to Nicolae and Elena Ceausescu in December of 1989.
They ran Romania between them, gave important government positions to family and friends, and their three children acted like spoiled Princes and a Princess (they had one daughter, two sons). Furthermore, when Nicolae died, his oldest son, Nico, was to take over (much like Kim Jong Il took over from his old man, Kim Il Sung in North Korea). This was not a Communist leader, this was a despotic king and his queen, an autocrat who put the tsars to shame.
Unfortunately, the Ceausescu's showed the WORST of Royalty the way they ran the country. It was "Love us, or die." Ceausescu called himself fancy names like "Genius Of The Carpathians" while Elena presented herself as a brilliant scientist (despite the fact that she flunked out of high school). Of course, when you're co-ruler of a country, you can have as many doctorates as you want, because of ghost written papers. She had utter contempt for the Romanian people, even once referring to them as "worms".
They lived in fancy houses, droves fancy cars, and wanted for nothing. All this while their people starved. They were building this big super palace in Bucharest when the Revolution of 1989 came. When Gorbachev said that Russia would no longer interfere in Eastern Europe, most of the Communist leaders knew it was over. Some, like East Germany's Erich Honecker, were forced out after massive demonstrations, but they all went without major bloodshed.
Sadly, that would not be the case with Romania. Giving up power would mean Nicolae and Elena would have to give up their privileges. Not happening. So when the uprisings against Communism reached Romania, Ceausescu ordered his troops to fire on the crowds. That was the straw that broke the camels back. Romania erupted into all out revolution. When the military switched sides, Nicholae and Elena tried to flee, but were captured. On Christmas Day, 1989, both were executed by firing squad.
I feel that if Nicholas II had tried to use force in 1917, the same might have happened to him and Alexandra (of course, it eventually did, but he had no way of knowing that). Nicholas stepped down when he knew there was no other solution.
Strange how they are parallels between the Russian and Romanian Revolutions (I remember watching events in Romania as they unfolded). However, there was one difference. While Nicolae and Elena Ceausescu were executed, their three children and the rest of the family was spared (unlike Russia, where the Bolsheviks murdered any Romanov they could get their hands on). Nicolae and Elena got a trial (even though the verdict was pretty much decided anyway, and many later said they should have gotten a fair trial, but there just wasn't time, the country was in total chaos). For N&A, there was no trial, not even a kangaroo one.