If those temperature rises are melting the ice from the inside, then the heat source is below the ice, not above it. No amount of driving small cars stops volcanic activity.
The melting is occurring at the plan-view
interior of the ice sheet because rising temperatures have shifted the ablation/melting zone farther inland. This increased melting at the cross-sectional
surface infiltrates through the glacier, transporting heat to the interior (plan and cross-sectional) of the glacier, most critically to the bed. At the bed, it "lubricates" (porewater pressure increases), which increases the flowrate.
If the ocean is simultaneously warming, that will cause melting from beneath the buyoant, ungrounded ice and float it, which will move the grounding line landward, which leads to even more buoyancy. Ice flow will increase, which can cause the ice sheet to expand, although it can also result in a collapse, as the unsupported ice can more easily calve.