Do you mean you will hold your BTC for six months? If yes, then stored it on a non-custodial wallet instead then just idle it there as long as you want and just wake them up once you are now ready to sell it. Transfer it to the exchange of your choice then do the conversion there.

No need to split funds into several exchanges. Just choose the reputable one once you are now decided to sell all your BTC. Read TOS too as there will be lots of changes after 6 months later.