A broken brake lever would have a big effect on the trip but it would be possible to keep riding (slowly). A broken clutch lever would be a showstopper. Levers are quite vulnerable and easily broken in a fall.
Rather than carry spare levers, I replaced the stock items with aftermarket folding levers. The idea is that they fold up rather than snap in the event of an unplanned dismount manoeuvre.
Folding brake and clutch levers fitted.
As a bonus, these levers are adjustable over a wide range, so they are more comfortable too.
Life is an adventure ride 