I had a doubles for my Roo. I found that snow piled up on the part of the cover that stretched between the tires and caused it to pull the covers off. I'm using 2 singles on my Mini Lite now and not having any issues. So if you're in a snow area, I'd recommend singles over doubles.
1988 Coleman Sequoia - popup (1987-2009) - outlasted 3 Dodge Grand Caravans!
2012 Roo19 - hybid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado 1500 Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10