The 5G millimeter wave (mmWave) New Radio (NR) systems are prone to blockage and micromobility effects. To improve service reliability, 3GPP proposed a dual-connectivity allowing UE to maintain links to two base stations (BS). However, this functionality is power-hungry resulting in a trade-off between performance and power efficiency. In this paper, we compare user equipment (UE) power efficiency, consumption, and battery lifetime for different intra- and inter-radio access technologies single- and dual-connectivity under different UE usage scenarios, micromobility, and blockage impairments. We evaluate five schemes: (i) BSs in FR1 and FR2 bands (NR-DC FR1/FR2), (ii) BSs in FR2 band (NR-DC FR2/FR2), and (iii) LTE BS and NR BS in FR2 band (EN-DC LTE/FR2), (iv) NR FR1, and (iv) LTE. Our results show that the LTE-only scheme provides three times longer battery lifetime as compared to its nearest rival-NR FR1 single-connectivity option. For dual-connectivity options, the best lifetime is observed for EN-DC FR2/LTE, and the worst – for NR-DC FR2/FR1. The difference between NR-DC FR2/FR1 and NR-DC FR2/FR2 schemes is negligible. Densification negatively affects all the dual-connectivity schemes as it forces UEs to switch between master and backup technologies more often. We recommend EN-DC FR2/LTE for low-traffic outage-sensitive applications, while NR-DC FR2/FR2-for heavy-traffic outage non-sensitive applications.