It is a big risk to go all in.
How much you have to invest is not really important for that decision, you should always diversify a bit even if you start with $50.
I suggest you to split in 3, for something a bit safe $200 in BTC then $150 in 2 others projects.
or you can try something like this :
$200 in BTC
$150 in STRAT
$75 in an other project
$75 in an other project
Should not invest in STRAT, I think this coin can not make much profit. Ideally, we should invest $ 300 in BTC, $ 100 in ETH and $ 100 left to invest in a secure ICO project. That is the way to reduce the risk