there's lots to do OR there are lots to do? [duplicate]

I read in a book:

There were lots to do on the farm: feeding the hens, collecting the eggs, going on a hay ride, visiting the ducks.

To me it seemed odd, that it should have been "There was lots to do"—but it was explained that this was the backward existential and was therefore correct. This seemed outmoded to me.

My question is: "There were lots to do" vs "There was lots to do...": is the backward existential still used?

NOTE: I believe this is not a duplicate of this or this as we're asking a question about the general usage of the backward existential in a particular situation.

'lots' can be singular or plural depending on what the speaker is talking about.

eg We'd better get started. There is lots to do. (i.e. a great deal, much, uncountable)

Are there any sandwiches left? Yes, there are lots in the fridge. (i.e. a great number, many, countable)