"What happens to an INFP once the rose-colored glasses come off?"
They become more balanced and healthier.
"Can you still be an dreamer when you've awaken to the cold, hard truth that is reality?"
Yes, the key is balance! It is hard to sway back and forth between being an idealist and a realist, but it can be done. Recognize what is impossible and let those go. Recognize what is possible despite a low chance of success and hold onto those. Don't over-stretch yourself with idealism. Talk to your friends who have different functions. Keep taking in information. Recognize that not everyone is Fi dominant and so their behavior is actually normal, not pure evil.
It is very important for an INFP to still dream, we are who we are, but that doesn't mean we can't grow or improve or learn other traits. We have to protect ourselves sometimes.
"Can you be still be an INFP type when you've become disenchanted with people?"
Yes. Learn to see the world and actions through not only your lens but the other people's lens. If it's an istp, learn to see it through his/her ti, not your fi. It will explain their actions and you will come to understand how other people work more. If you view every single little thing through fi, it will be very, very depressing, impractical, and not worth it.
I see Fi as this great quality for us (and for humankind
), but we need to not max it up to more than it needs to be, because we live in a world not dominated by Fi. Use Fi effectively. Control. Awareness. Other functions.
Know your own limits when it comes to holding onto ideals. Don't let yourself be beaten down because the only one doing that is you, attitude is important.
I am very much an idealist but that doesn't mean I don't accept reality. Sometimes, it is hard for me to see at the grits and the cold logic, but after every experience, I get a little better. I pick myself up a little quicker and recognize the problem before it gets out of control. I love my idealism. I have standards and I have integrity and I am proud of that, don't let the world or other people make you feel ashamed to have these qualities. At the same time, don't feel that you need to defend them every single time to every single person, that would just be exhausting. Do it when it can change something.
Also, I am not a rose-colored person about everything. I am quite a pessimistic person. And I think humanity is not as "awesome" as people like to believe. For every life, someone else is dying a miserable death. For every happy person, there is someone devastated. For every human being, some animal is without necessary resources. I tend to roll my eyes when people are overly sentimental about how extraordinary humanity is. But I am not a miserable person. I smile and laugh a lot. Balance!