This is a good and dedicated plan, but it can only be done by the rich, so I hope you are rich and have a stable income to fulfil it. That said, this plan will work, after all, you can't go wrong with those two coins in cryptos if you have the time to keep them for so long

However, I can only advise you to start this kind of plan when they are cheap. That will not only help you gain more but will also reduce the risk of staying in losses longer if they hold longer before they start appreciating.