Dunno if this is a genuine post or another cook up story to attract merits, but I'm going to say this to you anyways. In as much as I'm pro Bitcoin, I would not advice anyone to sell his/her valuable properties in order to invest in Bitcoin. It's volatile asset and your investment could appreciate or plummet. Also, Bitcoin investment is not a get rich quick scheme, and it take time. Do you even have knowledge of the market? Do you think your dad will be patient enough to wait for the value of Bitcoin to appreciate in order to take profit?
If they both have the investment goal/mindset of 4+ years, do you still have the same questions?
I agree that a short term mindset is gambling. No one should be gambling with their asserts...but it seems from the OP that the long term value is understood. It doesn't seem (from context) that the OP.is gambling with their livelihood.
That is something we do not know since the OP did not took the time to explain their plan, if they have actually took the time to read several books about investing and they have a general plan that includes a long term approach to the money they invested then this could turn out to be a good move, however if this is not the case and there was a strong dip before the halving, it would not surprise me if they panicked and sold their coins for a loss.