From my limited research, it seems that the majority position places Isa. 7:14 as referring only to Christ. Yet, there are some who see a double fulfillment, first in Maher-Shalal-Hash-Baz and later in Christ. The Spirit of the Reformation Study Bible supports the double fulfillment and the Reformation Study Bible (Sproul's) seems to suggest this as well, although not as strongly as the SOR). Gleason Archer's
supports the double fulfiment position, suggesting that one is the type and other the antitype.