Coleman Instant Up 8P for Family of 5?

Hi
just wondering if anyone has a view on whether this tent would comfortably fit 5 (2 adults on stretchers, three kids on thermarests). I can't find it set up anywhere in Melbourne to view it (and just missed the camping show!), but I spoke to someone at kangaroo Tent City in Sydney who said the sides slope quite a lot and it might be a squeeze for 5.
She suggested as an alternative the Black Wolf, which is much more expensive and heavier, on the downside, but also probably much stronger and more waterproof. Not sure which Black Wolf I would need (twin or plus).
Or another alternative would be to get a couple of the little three man speedy tents - Companion Exo or EPE Speedy.
I want it as a quick alternative to setting up the camper trailer on our trip up north, for places where we are only staying a night. I would prefer to all be in one tent as the kids are of an age that otherwise we would split up to have an adult in each tent. I know the Colman might not be so good in windy/rainy weather but I guess we could always do the camper trailer if necessary. I don't want it to be too heavy and it doesn't make sense to get a really expensive one when we are going to be pulling a trailer as well!
Any suggestions?