just a few ideas / facts
1º Constantinople will be applied in winter 2019. So still 1 year and 2 months away more or less. Many things can happen
2º Reward per block reduced to 2 ETH. If in 1 year ETH is at the same price, it will be an absolute NO GO for miners (although it's already a NO GO).
The reduction go into effect only in 14 months?
This Ocotber.
OP is clueless.
Also block time will be reduced from 10 to 7 minutes, so drop in profitability will not be 30%.
Somebody please correct me with relevant links.