Reliable GNSS positioning is critical for aviation and marine navigation, as well as in industries such as surveying, construction, and mining. As signals propagate through the ionosphere, irregularities in electron density can induce rapid fluctuations in amplitude and carrier phase, collectively referred to as scintillation. Scintillation can degrade the accuracy of both pseudorange and carrier-phase measurements and, when sufficiently intense, disrupt receiver tracking loops, causing cycle slips and loss of lock. In Canada, the effects of scintillation dominate at high latitudes, making the Arctic a region where GNSS availability can be particularly compromised. While scintillation climatology and characterization have been widely investigated, comparatively little attention has been given to its direct impact on GNSS positioning performance. This paper introduces an approach to evaluate how scintillation influences position solution quality through its effect on satellite availability. Data from the Canadian High Arctic Ionospheric Network are used to construct a scintillation sky map, which is updated at the cadence of phase observations to capture its spatial and temporal variability across the region. This map is then used to estimate the level of scintillation affecting signals received by a user, which in turn is incorporated into a weighted Geometric Dilution of Precision (GDOP) estimate. A consistent increase in correlation between 3D position residuals and the weighted GDOP compared to the standard GDOP demonstrates the potential of this approach and the value in expressing scintillation impact in terms of satellite availability.