This is a challenging question to answer for several reasons.

First, it's particularly difficult to detect cannibalism archaeologically for northern Iroquoian peoples. Early historical burial customs among the Wendat (Huron) and Haudenosaunee (Iroquois) creates similar markers as cannibalism. In certain circumstances, bodies would be exhumed, defleshed, and reburied in a large community ossuary-grave, usually as a prelude to the community moving the village to a new site. However, while the bodies are being processed for reburial or moved to the new burial site, bones--often marked by cutting implements--can be misplaced. This is especially likely for small bones, like the phalanges. However, the removal of fingers or parts of fingers was a common method of torture as well, which could precede cannibalism. Sorting out which bones actually represent cannibalism, and which were accidentally left during reburial is exceptionally difficult.

Second, historically, there's a lot of talk about cannibalism but very little in the way of direct observations. It always seems to be something that someone else, somewhere else was doing. The Jesuit Relations is the major historical source for Iroquoian peoples in the 1600s. In these documents, while the Wendat say they had once practiced cannibalism but had since given it up by the time the French missionaries arrived, the missionaries still reported that the cannibalism was taking place in this town or that (wherever the missionaries weren't) and especially among the Haudenosaunee. There's an incident in October 1635 when the Wendat had taken a Haudenosaunee captive and brought him back to the town where one of the French were staying. According to the missionary Paul le Jeune, there was talk of impending cannibalism among the Wendat as they watched the war party arrived with the captive. Since the captive was allegedly part of a group that had attacked and killed some French men earlier, the Wendat invited the French to the feast. Le Jeune refused, saying that they were not cannibals. Despite all that, though, the captive wasn't killed and eaten but adopted into the Wendat community. When the Haudenosaunee invade Wendake, the Jesuits elsewhere in New France are certain their compatriots were burned and devoured. But for all the early reports of cannibalism among the Haudenosaunee, by the time the Jesuit missionaries actually establish themselves in Haudenosaunee territory, accounts rapidly dwindle.

It's important to remember that the Jesuit Relations weren't written as neutral records of history. They were specifically fundraising and recruitment tools, and lurid tales of cannibalism helped sell French patrons on the necessity of the Jesuits' missionary efforts, as well as enticing a certain brand of priest with a pious deathwish for martyrdom to make the long journey to the New World. There's a modern trend to weed out the sensationalism of cannibal accounts in the early colonial accounts, which is a further complication in the historical record here if only for the risk of overcompensating and downplaying the real role of cannibalism in such societies.

Another issue here is the use of metaphors and idiomatic expressions. "To bring meat for the stew" was an ritualized expression used for presenting a captive to women for judgment (whether they'd be adopted or executed). I suspect the incident with le Jeune probably involved some miscommunication along these lines.

In the case of Ayonwantha and the Great Peacemaker, there is certainly symbolic value in that narrative, in addition to some truth. There are several variants of the foundation narrative. In other versions, the cannibalism issue takes a more prominent position, with Ayonwantha and Adodaroh being portrayed as practicing routine cannibalism. The Great Peacemaker doesn't necessarily convince Ayonwantha to give up cannibalism but that deer is the proper food for humans (Jigonsaseh convinced the Peacemaker that maize was also acceptable). Obviously the Iroquoian diet included more than just venison and maize, but those two food items are symbolic of the produce of the male hunter and the female farmer. Ayonwantha's cannibalism then is symbolic of persistent warfare--the real issue the Great Peacemaker was trying to deal with.

All that said, ritualized cannibalism was probably practiced among all Five Nations of the Haudenosaunee prior to and perhaps even after the formation of the confederacy, as well as among the Wendat and possibly other Northern Iroquioans. But it had either been abandoned as a practice prior to European contact or not long after--the timeframe likely varies from place to place. The evidence is too shaky to say much more than that.