I am not sure I understand the situation, and the situation does matter. I would not expect the interior temperature to drop to ambient temperatures. Even crawl space beneath a building with no basement would usually avoid dropping to the same temperature as ambient outside air.
Water has a fairly high heat capacity (drops temperature fairly slowly) so a few hours of direct exposure likely will not cause total freezing. The size of the pipe obviously matters considerably. However, a slow trickle of water through the pipe (where the pipe could freeze because of open exposure to ambient outside air) will add heat from outside (from wherever the water comes from) and that will limit the extent of freezing quite a bit, and thus avoid the likelihood that ice formation with volume expansion will impact the pipe.
That is the problem in a nutshell, after all: water expands when it freezes and when there is no room left inside the pipe to expand, then the pipe has to expand. Leaving a decent volume of liquid water in the pipe (by slow flow) provides room to accommodate the expansion of the ice portion.
It is very unlikely that a few hours of moderately sub-freezing temperatures will cause total freezing of the contents of a pipe.
If you haven't yet winterized (shut of water to any pipes that go outside and drained them), then now is the time. It won't be getting warmer any time soon.