Since iOS 8.3 was released, GPS remains activated in Airplane mode.

Posted by Apple Support May 9 2015.

You're riding a bike - get a hub dynamo and a cache battery. Keeping your phone charged won't be a problem. Discussed in detail in this thread.

You may find this article from the Salsa Bikes blog informative.
http://salsacycles.com/culture/tech_talk_understanding_drivetrain_rear_tire_capacity

Potato. Rub the lenses with cut potato.

The laptop is 325 x 223 x 18 mm (Asus Zenbook Prime).

Well, if you are coming to Australia I'll be happy to sell you my 26" Van Nicholas Pioneer Rohloff Titanium, but is size L (55cm).

Last tour I carried my 13" Macbook Air ( 17 mm x 325 mm x 227 mm) comfortably inside an STM laptop bag within a rear Ortlieb Roller pannier.

What are the dimensions of the laptop? What size bike? When are you planning to set off?

Relevate recommend the large sweetroll for drop bars. I think it would be best used for clothing and other items you don't need to access during the day.
Perhaps carry tent/mat/sleeping bag on the fork using Anything cages.

The other choice if you prefer a dedicated bike computer is the Magellan Cyclo 505. Whilst like the Edge it has it's own set of idiosyncrasies and issues, navigation is its strong suit, and yes it can navigate a track.

RonK-you make a good point and I have been managing battery life on etrex vistas for years on all the my multi day races. So normally I would agree disposable barratries are a better choice than rechargeable.  

However for the 2015 TDR I will be running a dynohub with buffer battery.  So I see no need to restrict myself to disposables and for the TDR & believe there can be distinct advantages to rechargeable GPS, headlamp and phone.

Anyone out there who own and use a Edge Touring unit and can comment on their experiences with it?

I'm currently running a SON dynamo hub and buffer battery and I've been managing multiple devices. It's become a chore and now I'm moving back to replaceable batteries where I can.

I've replaced my inaccurate and unreliable bike computer with a basis wired unit and ordered a new Etrex 30.

I'd urge you to research the Garmin forums carefully before you buy the Tour. Many owners have reported issues with them. You may find it a frustrating experience.

Under discussion recently here.

Units with internal batteries are a pain away from mains power. An Etrex 30 is a better choice.

My Inreach uses AA lithium batteries. One of my prime reasons for choosing it over the Spot.
Two sets lasted for a month on tour with around 5 - 8 hours use per day.

The Cateye Enduro is hard to beat. Simple one-button operation and a heavy duty wire. Cheap enough too.

I am currently building my TD "redemption rig" I have most of the parts, just haven't decided upon which frame yet. I am either going with Spot Ti or a Vassago Ti.

I have a Rohloff in a Ti frame. I suspect the thin, resonant Ti tubes amplify the noise emanating from the Rohloff in the lower  gears.
It's extremely annoying - and embarrassing when other cyclists comment.

And no, it hasn't gone away after the first oil change either...

I wouldn't go Rohloff again.

One word - Lezyne.

You may find the Tour Aotearoa route - top to bottom of interest. The latest track notes are here.

On the Kiwi Brevet route, the sections of most interest will probably be the Molesworth Road, Rainbow Road and St James bike route.

Heading south to Queenstown from the Kiwi Brevet route, you may find the Great Southern Brevet route interesting...I rode several sections a couple of years ago, the Southern Highlands are probably the most scenic part of the South Island. My tip is to take a telescopic fishing rod and some lures and flies.

There is a link to a course map .gpx file here.

I have an Inreach, and I'm very satisfied with it.
But it's not a GPS, it's a tracking and messaging device and an emergency beacon, and as such I believe is superior to the Spot tracker.

Just go to a bike shop and have some rivnuts installed.