"I just got back from a long trip (4k) through the cold." The 4k puts you on the edge of Valve Adjustment time. Could it be that on the trip you Valves clearances tightened up? And, people say you should do that before the Compression Test.

White smoke is an indication of un-burned Atomized Fuel or a Coolant leak into the Cylinder/s.
Bad Injector (if the smoke puffs out) or late Fuel Injection pump timing could also account for the white smoke.
Look for evidence of a Head Gasket leak.

Since it is easy to do check the Glow Plugs.

You would think that extended cranking would only have a chance to damage the Starting System.

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84 300D, 82 Volvo 244Gl Diesel