Brain Lake to Aura Lee via Hurdman Creek or Cauchon?  If your route is via Hurdman Creek, that can be a real slog down as far as Hurdman Lake. In other words, Brain Lake to Hurdman Lake can be buggy and marshy and boggy, especially if water levels are low - and the fishing isn't that great. Not my idea of fun.  But once you get to Hurdman, its fine.

There are better areas to paddle for a short two day.  What's your forcus for this trip? The Brent Crater? Fishing?

Hey Ash - I used Brain Lake access back in May 2014. So although this info does not apply to August, it's all I've got for ya!

Brain to Laurel won't be a problem in a day - as long as you don't mind getting your feet wet (but if water levels are good, you won't have to get your feet wet). You can easily skip the following portages; P130, P165 & P80 - again, note this was spring, I paddled them without scraping but you may have to get wet feet by August.  So really you only have 6 very short portages to contend with - you'll even have enough time to check out the crazy cliffs on Stretch Lake!

As for your exit day I'm sure it'll also be fine. A bit more walking but you'll be light by the end of the trip so it should be easier. Normally I'd say watch those Cedar winds, but the direction you're coming from the wind would give you push. If you have time, stop by the Gilmour campsite just north of the portage to Tecumseth and poke around. Some cool stuff hidden in the forest there.

As for access 27a. There is parking, on the west side of Brent road (not at the tower, but a few hundred meters further down Brent Road). There is space for about 6 vehicles and it is well signed. You cannot miss it - once you pass the crater lookout tower, just keep looking right. When coming up from Tecumseth, follow the signage carefully as to not follow one of the walking trail sections - they overlap in a few places but it's well signed.