I would cut them now or in 4-5 days .Then train the next growth around May 7-10 .It really has nothing to do w the frost,more the photo period of the plant.The 1st shoots are racers and produce far less and have much less sidearm growth.Proper cutback and training also affects ripening of the cones. Here is some info I found
C. Growth Characteristics
Although the early season growth rate and length of time for hop vines to reach the top wire of a trellis vary widely due to factors such as climatic conditions and growth and harvest management, the early season growth of Columbus is generally faster than the most aroma hops (such as Tettnang, Perle, Centennial, Saaz, Spalt, Mt. Hood, Liberty, Hallertau, Hersbruck, and Fuggle), and also faster than the quicker-growing aroma hops such as Cascade and Willamette. Such aroma hops are generally first trained between May 7 and May 10, and reach the top wire between June 20 and June 30. The aroma hop Cluster and the bitter hops Galena and Chinook are typically trained about May 15 and reach the top wire from about June 20 to about June 30. The bitter hops Nugget, Olympic, Eroica, and Columbus are typically trained about May 25 and reach the top wire about June 27 to about July 7. Among this latter group, Columbus typically grows slower than the other hop varieties at first, but then accelerates its growth and can grow to the top faster than Nugget on occasion. In other words, Columbus is a late maturing hop, and has an early growth rate that is typical for bitter hops and for Cluster, but it is a slow starter.