Do meters usually maintain their durability for a long period of time?
Yes, solid state meters (ones without dials, whetstone bridges and needles) are highly consistent
Solid State Meters tend to suffer from two sorts of failure:-
Cataclysmic events such as being dropped (repeatedly) or accidentally left out in the rain
or
Battery corrosion affecting either the terminals or wires
Of course almost all electronic devices are susceptible to Coca Cola and Sea Water.
Personally, I carry at least two meters with me, a Spot Meter and an Incident Meter, which have different strengths and weaknesses but give some level of back-up should anything go wrong with the other
With a 5x4 kit you will not be travelling light in any case
Martin