In my opinion by investing all savings in cryptocurrency no good idea, I think maximum 80% of all savings and other 20% keep on fiat. Because we need to keep Fiat for urgent needed, and when this happen and the price of cryptocurrency down then we should be withdraw it. So that we are in loss. In my research good coin for longterm investment is BTC, ETH,WAVES and DASH by portofolio 50% BTC and other 50% for those altcoin.
I think you should divide it into three parts, the first part is for your investment this is the half of your saving or 50%,but make sure pick the best cryptocurrency to invest second is for your saving make it 30%, and for the third for your emergency need and make it 20%
Go for the multiple coins would be good for the altcoins investment but if see with the comparison with bitcoin and altcoins you need thing that which coin is best in the market and value would increase future all that time.
In such cases, bitcoin is every time best investment option so you can invest all your money only in bitcoin itself.