The record-breaking 51-3 victory at the Millennium Stadium meant the 2012 and 2013 tournament winners finished third in the table ahead of a tough two-Test series with the Springboks in the summer and Gatland is confident they will build on that platform in Durban and Nelspruit.
"We'll take a lot of confidence from that win. The six-day turnaround was tough. It was tough mentally as well knowing that you're out of the tournament. For the players to respond and really pick themselves up was fantastic," said Gatland.
"We've got a really tough tour to South Africa ahead. We know how tough a place it is to tour so the planning's already under way. We're trying to manage the players. A lot of them will potentially be finished quite early in May so it's about giving them a bit of rest time and then getting them back and conditioning them for the hard grounds of South Africa.
"We're hoping to take a slightly bigger squad and we're looking at a midweek game potentially against the Southern Kings in Port Elizabeth so that everyone's a part of the tour."
Gatland knows that Wales will have to be at their best to leave South Africa with an historic series triumph but he sees no reason why they can't repeat the form they showed against Scotland and France in recent weeks and throughout the previous two Championships as a whole.
The New Zealander has been impressed with the way Wales have responded to adversity after defeats to Ireland and England and, with analysis of how to progress already well under way, he is keen to kick on in the lead up to next year's Rugby World Cup.
"There's no one tougher on ourselves than us as coaches or players. We set massive expectations for ourselves and the media put a lot of expectation and pressure on us as well. We know we've got to keep working and keep improving as a side," added Gatland.
"We probably just dropped off a bit, and that's understandable. A few of our players aren't where they were physically 12 months ago. That can sometimes happen. We did have a number of players at the start of the tournament who hadn't had a lot of rugby as well.
"What we've learnt is that teams aren't playing a lot of rugby against us so we're going to have to change and deal with that. In the two games that we lost, both teams kicked a lot more than we did, particularly Ireland who played a lot of one-pass rugby and tried to negate our strengths. As coaches we're going to have to assess that and work and change going forwards.
"What's pleasing about this side and this group of players is the way that they can respond and change. If something doesn't work out or doesn't happen for them, I'd like to think that we've been able to respond positively with a performance in the next game."