Are they still just cuttings. Why not continue their growth cycle by putting them on your window sills. Just don't let them be touching the window glass and turn them 1/4 turn every day.
Whether you put them under plastic is up to you but draw them back somewhat from the sun's rays that can build up through the glass. A cutting cannot survive given a place where the temperature falls to near or below the freezing mark.
They should be kept damp until roots are well established, then transfer to soil or combo of perlite/vermiculite or vermiculite/peat moss. During the initial phase, the use of a growth hormone is also up to you but is recommended. | 
