Large outdoor tank ! (Knighton LD7)

My smallish pond has a leak and it needs rebuilding and lining. This can’t be done until October or November . I have a lot of newts 1 large goldfish and plants. Last time I emptied it I used dustbins but it is too long a period to leave them in a bin. Any ideas, outdoor large tank container that is square or rectangular! Suggestions offers welcome.