Custom Shimano 3x11 drivetrain I have a Trek 720 disc which came with a 2x11 Shimano 105 drive train setup.

When it's fully loaded for touring going up steep hills is just too hard - I'm barely heavy enough to push the pedal down.

My idea is to put a triple on the front.
I've found all these Shimano 105 triple components available so hopefully compatibility should not be an issue: 


Triple 10 speed 5703 Chainset
5703/5700 Left shifter
10 speed 5703 Front derailleur


My concern is that the chainset and derailleur specifically state 10 speed - and I want to use them with an 11 speed cassette. I also plan to tour in some potentially quite remote areas so reliability is a priority for me.

Do you think this setup will work ok?
No you would either have to use a 2x11 speed drivetrain or a 3x10 speed drive train. You can't pick and choose and any hacks would reduce reliability. 

Using the 10 speed 30/28 is the same gearing as 34/32 on the 11 speed so no advantage on the change.

For remote touring maintenance is as important or more important than gear selection. 

For long distance touring 10 speed would likely be more available on the road as 9 speed is being gradually phased out and 11 speed still quite new so would factor in what stock bike shops held.