Masonry Wall humidity Logging: what relevance of a local "air humidity probe" inserted in a hole drilled deep into the wall

Question

INTRODUCTION:

In the countryside, for a very very  old house that is a sparsely occupied, and  with reccurent and severe humidity problems:

I would like to remote-monitor and log the wall humidity over the long term using a multiplicity of local probes (at different heights and lateral positions).

My goal is 

a) near the roof-wall regions, to get an early warning of eventual water infiltration due to  eventual cryptic default in the roof

b) to monitor the wall humidity along its height and at different locations, and get early warning of cryptic water leak (from plumbing when the house is occupied), or resulting from  events of a dangerously high water table, insufficient air flow inside the house when unoccupied, etc...

MY QUESTIONS:

A) WHAT WOULD BE THE RELEVANCE of monitoring the WALL HUMIDITY at different heights and locations, using cheap digital local probes, that measure RELATIVE HUMIDITY AND TEMPERATURE OF AIR

and placing those temperature+humidity-probes into holes DRILLED DEEP INTO THE WALL (and sealing the entrance of the holes, so that the air inside the hole is at equilibrium with the humidity of the wall)

B1) what would be the connexion between such measurement, and the water-content of the wall at the measurement position ?

B2) Should one expect, in the case of a diffuse water front at the top edge of the water infiltration (e.g. not an abrupt front), that the air-probe embedded into the wall will give anayway a quasi-saturated 100% near  the top edge of the diffuse front ?

C) Is gravity a relevant factor here (for this particular measurement , a 1m thickness of the wall, and taking into account 2B) , at say at either 2m, or 3m, or 4m, or 5m  height above ground ? (considering https://doi.org/10.1098/rspa.2007.1855, and the 1m wall thickness)

ADDENDUM:

The walls of this house are about 1m thick, assembled with earth, comprising two stone faces and filled with earth in the middle; facade length about 10m, minimum wall height 5m; no crawl space under the house)

The digital temperature-humidity probes I am considering are for example the Sensirion  SHT31 or SHT41, (about a buck a piece), expected to give a +-2.5 % precision for relative humidity of air.