Prepping the Fuel injection on a R1150GS

[Warthog]

We are going to ride Argentina and Chile later this year: 3 months, Sept to Dec. Its a UK bike and will have a Y piece (with Lamda Probe) to save the cat from the risk of crappy fuel and to save a bit of weight, and I may stick on the Remus revolution can with or without baffle. (Without only because I like the noise, but the bike's longevity is the priority!)

My question is do I need to have the injection re-mapped to suit the Patagonian/Andean air and fuel. A Y piece and/or can will lean the mixture already and the added drop in O2 in the higher altitudes may put my bike's engine at risk. I don't want to whole a piston in the middle of the altiplano!!

What to do? Do I remap or not and what combination should I use?

Cat and Standard can?
Y piece and Standard?
Y piece and Remus (baffle in)?
Y piece and Remus (baffle out)?

Thanks, Nick