According to the rule book you can run TC on carpet as well, so you don't necessarily have to find 2 venues close together. A clever reading of 1.0.4 reveals that technically the surface is only recommended to be indoors on carpet, so maybe there is a possibility of running 12th on asphalt (as has been done many times in the past) as well.
Originally Posted by IFMAR WC Electric Track Rules
1.0.1 The IFMAR Electric On-road World Championships will be a 4 day event for the ISTC class and a 3 day event for the 1/12th class. The events may be run consecutively at the same venue or as consecutive separate events at different venues at the same regional areas
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1.0.3 The track surface for the ISTC class can be either asphalt or needle carpet.
1.0.4 The track surface for 1/12th Class is recommended to be indoors on standardised needle carpet.