This is indeed an atypical temperature range.

If these temperatures are based on some pipe spec, it may not be the actual design temperatures of the line in question. Consult the process engineer.

If, however, these are actual design temperatures of the line, yes, the "full expansion" range is required.

If so, I would caution you to understand where you're lifting off supports, if anywhere, and see about fixing that. Otherwise, expect to treat it as a 650 degree line.