Emma Wilby goes on at some length describing the general religious ignorance of the poor in Scotland and elsewhere. And describes the lack of will that the Catholic church in particular had, in educating the poor about the basics of their religion - expecting them instead to simply do as they were told:

"How far lay religiosity existed in the early modern period, and what form it took is a matter of ongoing debate among historians. Traditionally the latter have emphasised that since its emergence in Scotland in the sixth centuary the Christian church had, as in other parts of Europe, been primarily concerned with maintaining social stability through the establishment of outer conformity. In other words, it was less concerned with what people thought and believed so long as they behaved properly. In Catholic Europe, as John Arnold has recently claimed, the Church's primary consideration was 'the demand to do certain things, rather than the demand to know'.
[...]
in the early modern period ministers made more of an effort to encourage inner piety among their parishoners than had their Catholic predecessors. ...
University educated ministers laboured to make their abstract intellectual religion of the elite accessible to to a largely illiterate congregation."

That's not to say that as Jack says I imagine some kind of covert formal pagan worship of Ceres or some-such. I think the poor were too busy working and surviving, to care too much about the historic or symbolic meaning of their religious figures. But I can imagine a pretty pragmatic "This is the new boss, same as the old boss" type of Christianity among the rural poor as they got on with the business of working and surviving.