LOVE this thread.
i too like many have gone for a swade, mine was in very early spring near Canmore many years ago. stupidly tried to cross the river, but apart from the heart-stopping cold water i quickly realized my waders were not going to fill up or cause me to drown, although i was worried about a log jam downstream. almost died getting back to my vehilce tho and i remember stripping completely down right beside a family on a picnic to get some warm clothes on [not pretty] - i was too hypothermic to care.
since then i have actually intentionally jumped into the river with my waders on to retrieve a hat [hey, it's a lucky hat], and again apart from getting a little wet i was never in any danger. plus it was a nice day in August.
like Harps posted, the key is: don't panic, feet downstream, backrow with your arms and kick your way to the shore when you can.