Well ETH was actually suppose to go POS back in Summer of 2016. Now 5 years later and still no POS. One thing that ETH dev team is great at is missing deadlines. So there is no concrete answer when it will go POS.
You bigger issue is that ETH sustains its >$2500 price and that the difficult stops growing. Apparently there are many high tech ETH ASICs out there and it will keep increasing the hashrate for the near future, not good for GPU miners.
POS is your last worry right now.
Good thing diff is not growing anymore im following etherscan it highest hashrate was recorded at 650TH now it is slowly going down today 600TH.So far we know eth dev team will do nothing about asics so we all need prepaired for low profit. The latest asics will make profit way too low this time i think. Last bearmarket there wasnt so powerfull asics but now they are serious. When 160Mhs asic deployed it was low but now people talking about asics at 2-2.8Ghs it 20x more powerfull than it used to be.