The Ford squad put an end to a rough run of results last Sunday when Tanak and co-driver Martin Jarveoja scored a first victory since February's Rally Sweden triumph.
Heading into Chile, the British outfit had scored two podiums in a campaign that had been blighted by misfortune and reliability woes.
However, Tanak and the team were unstoppable on Chile's tyre-punishing gravel roads. The convincing victory was set up by an inspired call to take hard tyres for Saturday's abrasive stages.
"It's definitely nice to have a positive outcome from a week after what feels like a long time," said Tanak.
"Altogether it is definitely quite close to a perfect weekend. It seemed somehow very different from what we have to do normally.
"It was not too much about pure performance at all, it was a lot about management and how to get through the loop, it was a different kind of challenge. These positive vibes are always helping so I am sure it's been a great week for the team."
M-Sport's future competing at the WRC's highest level is yet to be confirmed as it continues to secure sponsorship and budgets for 2024.
While the team is unable to commit to a 2024 campaign at the moment, team founder Malcolm Wilson has reiterated that it has no intention to halt its Rally1 programme.
However, victory in Chile has provided a much needed morale boost for the squad with Millener stating that the result will help its future plans.
"I'm really happy with the weekend and I think the whole team can be very happy as they have been pushing to replicate what we did in Sweden," said Millener.
"I think we knew when we came here we had an opportunity to do well.
"We did our bit and we have to take our hats off to Ott and Martin. They did a fantastic job all weekend and really pushed when needed and controlled at other times, and we came away with the win.
"Within the team, the result is massive for us. The motivation was low and the frustration was high but now everyone's mood has been lifted. This win was not inherited, it was a proper win.
"It [the future] is still quite difficult but let's see what happens. We can only prove that we have a team and a car capable and we will be pushing to use that to make sure we have the strongest line-up possible next year, and obviously hope that we are competing next year.
"It is nice to show that the car still has the ability to win and that is one of the biggest things. It can only help when we get a result like this."
