Altcoin investment for 1 year is not a bad idea. This is a common length of time to decide for a certain coin if it would survived in the market. I think it would be better to target time like that compared to 5-10 years.
10 years is a whole era for cryptocurrencies, this market is the most volatile, it grows and changes much faster than any other. I think it would be better to point a target in USD value than in years/months, never know how fast the things may change.