I've made some changes to our plans for later next week. Our original itinerary was as follows:
... Fri 18-5 Lochmaddy (N Uist) to Castlebay (Barra)
Sat 19-5 Barra to Vatersay then cycle all the way back to Lochmaddy for 1600 ferry to Uig
Sun 20-5 Cycle Uig to Mallaig
Mon 21-5 Cycle Mallaig to Tobermory via Kilchoan.
The last three days were all hard going and there was a good chance we would fail to get to the Lochmaddy - Uig ferry on time.
Having studied the ferry timetables again, we've found what we think is a much better alternative:
...Fri 18-5 Lochmaddy to Lochboisdale (S Uist)
Sat 19-5 Lochboisdale to Eriskay, Barra & Vatersay.
Sun 20-5 0920 Ferry from Castlebay to Oban
Mon 21-5 Oban - Craignure (Mull) then resume original itinerary at Tobermory.
This cuts out a lot of repetitive / wasted mileage and I'm hoping it will work well!