Of course it will drop again.
I would consider $1250 as a near certainty at some point in the next six months, even if this rally reaches all the way to $3000.
And as the poster above me mentioned, sell a portion. Sell even just 20% of what you plan on selling at $2000, then list another 50% of what you planned at $1998, then list some more at $2100, 2200, etc.
Never go all in, or all out.
It can't hurt. I went all in at 300 and 600 and I've made some nice profits, still holding. Depends mostly if you like taking risks or going safe, personally I like taking risks with crypto as I've made far more doing risky shit than planning out something and following the plan. Just sell when you feel comfortable with your profits and buy something nice to feel better; historically, if you've bought coins before this month at any exchange price and sold right now, you'd have made money. This is including Gox prices which were incredibly inflated.
The thing about risk is that you pretty much can't gauge it.
My suggestion to you, or anyone, if you are planning on 100% holding for a much higher price than now is to consider if even your dream price actually changes your life. Will $4,000/BTC materially change your life? I don't mean buying "something nice," that's just stuff. It will probably be thrown away or destroyed in 10 years.
I mean, how do current profit levels effect your actual day to day existence? Would it allow you to buy a house? To get a degree that you really need for your career? To retire?
If BTC doubles do any of those big picture things change? No? Then not a significant material difference. You might consider selling 20% if there is no significant material difference between doing so now, versus in this hoped for future of even higher BTC prices.
Think about what is actually being gained at different levels, as well as what is lost. Then make a decision. Just doing it because it's risky is utterly illogical. If you actually see a major change to your day to day existence that is mathematically possible, then you can at least make an informed--if risky--decision. But remember, the most likely event based upon BTC history is that at some point you will be able to buy back in for less than you sell for today.