Two-dimensional quantum gases provide a distinctive setting in which enhanced thermal fluctuations, finite-size effects, and two-body bound-state formation are intrinsically intertwined. In this work, we study a single attractive impurity immersed in a finite, weakly interacting two-dimensional Bose gas, where finite size stabilizes a nonzero condensate fraction by introducing an infrared momentum scale, thereby enabling a Bogoliubov description of the bath. Using a hybrid approach that combines finite-temperature many-body scattering theory with path-integral Monte Carlo, we analyze the impurity quasiparticle energy in the condensate and normal regimes. We employ different approximations for the bath in the two regimes and therefore restrict our quantitative predictions to temperature ranges that lie outside the crossover between them. The infrared scale generates a phonon-activation temperature below which the impurity energy remains nearly temperature independent. Once the resolved phonon modes become thermally populated, enhanced impurity–bath scattering competes with condensate depletion and the narrowing of the phonon window, shaping the coupling-dependent temperature evolution of the polaron energy. These results suggest that attractive Bose polarons may serve as sensitive probes of finite-size thermal fluctuations, phonon dressing, and bound-state physics in low-dimensional Bose gases.