What is the service wire sizing based off of on a temporay power pole?
According to the National Electrical Code 2017, the service-entrance conductors should be sized based on the loads being served.

National Electrical Code 2017
Chapter 2 Wiring and Protection
Article 230 Services
230.42 Minimum Size and Rating
(A) General. Service-entrance conductors shall have an ampacity of not less than the maximum load to be served. Conductors shall be sized to carry not less than the largest of 230.42(A)(1) or (A)(2). Loads shall be determined in accordance with Part III, IV, or V of Article 220, as applicable. Ampacity shall be determined from 310.15. The maximum allowable current of busways shall be that value for which the busway has been listed or labeled.
(1) Where the service-entrance conductors supply continuous loads or any combination of noncontinuous and continuous loads, the minimum service-entrance conductors size shall have an allowable ampacity not less than the sum of the noncontinuous loads plus 125 percent of the continuous loads.
(2) The minimum service-entrance conductor size shall have an ampacity not less than the minimum load to be served after the application of any adjustment or correction factors.