When i lived in the frozen North I used to warm the epoxy by letting the bottles sit in a pan of fairly hot water for 10-15 minutes. Mix normally and apply, then put the plane / part under a couple lamps with 100watt light bulbs about a foot or so above it. This was in a basement workroom that stayed about 40-50 degrees unless I had a portable heater going. The lamps kept the rea under them at about 70, and the epoxy usually cured fully overnight.
Your other option is to move to FL, AZ, or another warm place- Worked for me!