Thanks for the question Rachel!  Looks like we've got the long specs on external dimensions of the regular bag - we'll get that updated now!
Both are 193cm externally, but realistically the external dimensions are not relevant.
You need to adhere to the stated max user height, which is 183cm on the regular bags.

The Journey will zip to any size of the classic Trek bags.

Hope that helps!

G'day Jason,

The Trek, being a unisex bag, only has left zippers - if you want to join this to another bag you'd need a womens specific bag such as the Journey, or Ascent, which have the right hand zippers.

G'day Leah,

It's a little tricky to give an exact size of the compressed bag, as depending on how much you compress it you'll end up with a longer/skinny package, or a shorter/fatter package. Our packed dimension on the listing is in the uncompressed state, they will compress about one third of the size, and end up about 25cm long. Have a look at our product video too, right at the end, Ben shows the size compared to a 1L Nalgene bottle which might help gauge the size and shape too.  

G'day Cameron,

I would suggest considering the Tk2 or TK3 as the Overland track has extremely variable weather, and it's not unusual for walkers to experience snow in March. We'd suggest at a minimum that you look at the TK2 (-1).

G'day Amanda,

It probably depends on what kind of sleeper you are - hot or cold?  And also whereabouts you'd be camping?  The Tk2 does have the option to be fully opened out and used as a quilt or zipped with just the foot area open, so you have the versatility of being able to use it across the seasons.  Unless you're in a heatwave I reckon you'd be fine to use the Bag in summer.  Hope that helps :)

G'day Scott,

The compression bag supplied with the Trek Tk2 isn't waterproof so we'd suggest grabbing a Compression Dry Sack in the small size.