Isotherms update just covered this exact thing. Trop PV over NP *should* be a relatively short-lived feature irt geopotential heights in that region:
"Most of the high latitude blocking through the first 10 days of January will be over the NAO domain, as the z150 and tropospheric vortices will be displaced near the north pole, resulting in lower than normal geopotential heights there, at least initially." - Isotherm