I actually had to resort to a plug-in heater for mine.
Got it mostly installed, covered the whole thing with a big tarp, brought out the 110 V space heater and plugged it in inside the truck.
Went off to work and when I came home that evening I was able to attach the top at all points.
Ended up being a really great drum tight install, but took the extra effort.
Hence, the usual recommendation to bring the top indoors for 24 hours before trying to install it. Or that hoped for sunny day sitting in the sunshine.