  We present new VLT/MUSE observations of the Hubble Frontier Field (HFF)
galaxy cluster MACS J1149.5+2223, lensing the well-known supernova "Refsdal"
into multiple images, which enabled the first cosmological applications with a
strongly lensed supernova. Thanks to these data, targeting a northern region of
the cluster and thus complementing our previous MUSE program on the cluster
core, we release a new catalog containing 162 secure spectroscopic redshifts.
We confirm 22 cluster members, which were previously only photometrically
selected, and detect ten additional ones, resulting in a total of 308 secure
members, of which 63% are spectroscopically confirmed. We further identify 17
new spectroscopic multiple images belonging to 6 different background sources.
By exploiting MUSE data, in combination with the deep HFF images, we develop an
improved total mass model of MACS J1149.5+2223. This model includes 308 total
mass components for the member galaxies and requires four additional mass
profiles, one of which is associated with a cluster galaxy overdensity
identified in the North, representing the DM mass distribution on larger
scales. The values of the resulting 34 free parameters are optimized based on
the observed positions of 106 multiple images from 34 different families, that
cover the redshift range between 1.240 and 5.983. Our final model has a
multiple image position rms value of 0.39", which is well in agreement with
that of other cluster lens models. With this refined mass model, we pave the
way towards even better strong-lensing analyses that will exploit the deep and
high resolution observations with HST and JWST on a pixel level in the region
of the supernova Refsdal host. This will increase the number of observables by
around two orders of magnitudes, thus offering us the opportunity of carrying
out more precise and accurate cosmographic measurements.
