Slurry Mix Only 3 hours work time?

[The Famous Forry]

I have a slurry mix I bought for my porcelain tile job. I am a novice but see the slurry mix is workable for around 3 hours. I have about 44 60x60cm tiles to lay on mortar bed. I would guess it take me a lot longer than 3 hours though so would you mix a third at a time. My slurry mix is 17kg bag supplied in bucket ready for self mixing. Please advise, thanks