I've always run two sets of numbers for early retirement...one assuming I got full SS and pension, and one assuming I'd get nothing. A couple years ago, I took the pension out of the equation by taking a buyout. It would have been a small pension...$349 per month starting at age 65, in 2035, but not adjusted for inflation. $349 wasn't much when I was working for that company, is even less now, and might buy a case of cheap beer by the time 2035 rolls around. Anyway, the buyout was around $14K.
This morning, I just re-ran the numbers. Right now, assuming full SS funding, and taking it early at 62, I have a 94.6% chance of success of retiring at 50, and a 100% chance of success if I hold off until age 51. This is assuming I max out my 401k until I retire, and a budget of $60K per year when I retire, which is more than I live off of now.
Anyway, my projected SS is around $15,500 annually if I leave the workforce at 50, and ~$19000 if I wait until 51. If I assume no SS whatsoever, then my success rate of living off of $60K per year drops to 79.6% if I retire at 50, $83.9% if I retire at 51. But, if I hold out just a bit longer, it goes up to 93.5% at 52, and 97.8% at 53.
So, taking SS out of the equation completely only pushes my retirement back around 2 years, if I still want that lifestyle. On the flip side, if I want to take a financial haircut instead of pushing my retirement date back, if I drop to $55K per year, my success rate is 87.1% at 50, 97.8% at 51.
Chances are, they won't take SS away completely, but instead mess with it by either raising the contribution rate, reducing the benefit somewhat, changing the way they calculate inflation, or some combination thereof. So, I'm not *too* worried about it affecting my retirement plans. I'll be annoyed, since I paid into it all those years, but it won't be the end of the world for me.