yeah dude, 140's are massive! especially compared to a 98 width which is like a Mantra or something (btw pick up a mantra for your next one quiver ski, especially for Michigan's varying conditions).
anyways, if you are looking just for powder then the length of the 190 plus the 140 underfoot might not be too bad as the length might give it a bit of a stiffer feel, plus bouncing around in the powder is heaven on earth!!
my suggestion, the 190 height will be just a bit shorter than you but maybe just a little less under foot and a touch stiffer (especially cause that's your preference anyway). if you only get one day of powder a year, then definitely rent a pair of demo powder skis from the base of the mountain and usually they will let you stop in a couple times to swap them for another size/style/make of demo skis, just show up with a 6pack of PBR for the rental shop dudes!
good luck man!