Cardiff cemented their quarter-final qualification with a 22-16 victory against Stormers to set up a rematch in South Africa.
The game will be played in Cape Town which means there are no issues with altitude, so Cardiff will begin the week training in Wales and finish it in South Africa.
“The beauty of it in Cape Town, it’s at sea level and it’s winter now,” said McNally.
“So there’s nothing too major to prepare for. We will do most of our training up here, then go down for a smash and grab and see where we are.”
Stormers will be strong favourites as they aim for revenge.
“That is set up perfectly for us,” said McNally.
“You see the best of us when we’re underdogs. No one gave us a chance last Friday and we come out with a bit between our teeth.
“You can say there’s a few challenges next week but we go down there and do something.
“We know exactly how we want to play. We’re genuinely excited to be still playing rugby at this time of year when others are off.
“It gives boys a new experience of playing play-offs and it’s an exciting time.”