Another Tire Question for Staggered Setup, Need something for Winter

[SLX5]

I have checked most of the links already about the various tires. I got 4.4i with the sport package. Cannot afford or have the space to have dedicated snow tires and wheels. Live in KY, we get frequent snow storm but only a 2-4 inches most of the time. Looking for tires that is good in wet/dry/snow.

After a lot of research, I came across the following

Continental Extreme Contact DWS
Firestone Destination
Michelin Latitude Tour HP

Firestone does not have many sizes so its out. Michelin would be the last resort. I would like to use the Continental Extreme Contact DWS but they don't have the exact size.

Here is the stock data
Front - 255/50/19 - Sidewall 5.0in, Radius 14.5in, Dameter 29.0in, Circum 91.2in, Rev/Mile 695

Rear - 285/45/19 - Sidewall 5.0in, Radius 14.5in, Dameter 29.1in, Circum 91.4in, Rev/Mile 693

Not much of an issue finding the front, but the question is to the rear tires

1) Is it possible to mount a 275/45/19 on the stock wheel instead of the 285? Will it hold?
2) With the 275/45/19 - Sidewall 4.9in, Radius 14.4in, Diameter 28.7in, Circum 90.3in, Rev/Mile 702

In other words, the tire diameter would be off by 0.4inches, and Cirsumference Difference would be 1.1inches. Would this mess up the tranny?

Any advice would be greatly appreciated!!!!

Forgot to mention, I could reduce the front to 245/50/19, if it can be mounted on the rim again. then the stats would be 245/50/19-Sidewall 4.8in, Radius 14.3in, Diameter 28.6in, Circum 90.0in, Rev/Mile 704. and wouldn't have any issues at all!!

At the end of the day, Is it possible to mount a 245 width on a 255 and a 275width of a 285??