Under the new residence-based system, if a non-UK resident leaves their UK estate to their non-UK resident spouse under the terms of their UK Will (1) is their estate exempt from IHT under the Spouse Exemption (is there any limit to the Spouse Exemption in this scenario) and (2) can their spouse’s estate benefit from the unused NRB and RNRB to leave £1m of UK assets free of IHT?