I generally book tables for 2 when I'm solo - that usually works...but if a restaurant dominated by 4-tops was completely impossible to book for 1-2, but readily available for 4, I'd probably book it. As mentioned, a long known flaw in Disney's reservation system for solo dining...I can't tell you how many times there's no availability for 1, but switch to 2 and suddenly dozens of times are available. Parties of 1 or 2 would use up the same table size, so there shouldn't be such a discrepancy.