I've been on HT since March and have hot flushes every 30 to 45 minutes day and night. Hasn't really improved. Luckily they only last for 3 or 4 minutes. You seem to eventually get used to kicking off the duvet and then pulling it back on at night; I only wake 3 or 4 times a night nowadays, although my smart watch still notes my regular sweats activity.
I don't really go for this cotton /linen clothing idea, as the sweat shows too much. (During some of my flushes I am literally dripping from most of my body!). I've invested in a number of technical polo shirts. These clever man made fibres can cope with the sweat, wick it away fast and stop you looking too much like a wet rag. A zipped top is also a good idea to aid adding taking off layers fast. I find my body goes cold before a sweat, then very hot and afterwards I'm cold as the sweat evaporates.
I've also invested in a good hand held fan. Invaluable when you have to stay where you are, for example out having a meal.
Good luck.