The idea of HODL is entirely up to you and your greed level. If you wish to have trust in the project, then, its entirely up to you.
Until when do you have the mindset that holding bitcoins is greed?
I don't think holding is greed because they have their own targets for a certain period of time before taking profits. Being a holder is a good option to expect a commensurate return, so it is not true that holding is greed even if they expect higher returns. If you understand that investing takes time to pay off, then you shouldn't say that holding is greed.
I don't think that holding bitcoin for long is greed. No, instead for you to be able to hold your bitcoin for long needs patience and self discipline with a lot of sacrifice which a newbie might see very hard to accomplish. What is greed is trading or selling your bitcoin because you feel that is the best way to add more bitcoin to your portfolio which is a very wrong idea,because you will always end up selling at the wrong time thinking that it is the right time to sell off some bitcoin. Most newbies always feel that after buying and the price pumps a little that is the right time to sell and the end up using 100% of their funds to invest in bitcoin. And when the price didn't move up as they planned,instead the price goes dip,they and sell off because they lack the knowledge on how to have a good profit on bitcoin by holding for a long time. Well we all have our reasons on why we are buying bitcoin.