Keep my garage moisture free

Dehumidifiers typically work at 65 degrees and above. At 58 degrees they freeze up.
Moisture barrier on the warm side, here in manitoba its on the inside, my understanding the vapour barrier in warm climates goes on outside. Correct?

I thought the foil type insulation was more effective due to its reflective quality, as its only r7 for the single layer.

here is r20 in walls and r40 in attic.