Its a great idea seems it will be like a savings funds that can get higher returns in the future, Make sure to keep it safe where only you or your wife can access it, while it is safe that it will only you who knows it, there are events we can’t control and it’s better to have someone know where to find or use it. And still keep on monitoring the price whenever you buy. Alongside of holding bitcoin also try to have atleast a small portion for  a emergency fund or educational fund for your child so if ever the price of bitcoin still isn’t that high at times you will need it, there is still a fund a alloted for his school or emergencies that needed a money readily.