Towing in the Outer Hebrides

We are planning a trip to the Outer Hebrides in 2015 and are planning to spend a few days on Barra and a few days on the Uists travelling beween the two on the Eriskay to Ardmhor ferry, but aren't sure about the road to and from the ferry on Eriskay. We will be towing a single axle 4 berth caravan with a Volvo v70. I, as a non driver think we will be fine but my husband (chauffeur) isn't so sure. We are aware that after you leave the A865 and join the B888 the road narrows but has anybody towed this route and have we any need to be worried?