It will depend mainly on the bitcoin price in USD. As long as it doesn't increase significantly, I'd expect small difficulty jumps, like the last months.
I have bought some TH1 to lend them, so I can find out how it works in practice.
I believe there is no reason for ASIC owners to turn their miners off. At least when BTC price is higher than spended electricity. And "higher" doesn't mean "more than $500", it's more like "more than $50".

So I will not going long with price higher than 0.9 BTC.
And don't forget to monitor this:
https://bitcoinwisdom.com/bitcoin/difficultyUnless mining costs decrease or bitcoin price increases, I wouldn't expect difficulty to keep increasing. It can happen for a while, if they are new miners or miners expand their business. But after that, profits/costs will have to go up to make difficulty also increase.
I bought a bit of HT1 to see how it works. But I wouldn't now, 1.234 is too much even when taking into account the interest of lending it.