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Quarter panel clearance is the obvious consideration. Maybe some member here will have experience with that exact wheel and can get you in the ball park, but I can give you a comparison to my known rear tire/wheel combo using tiresize.com. I have 275/60-15s mounted on 15x8 rims with 5.5" backspace (+25 mm offset) with right at .6" clearance between the sidewall and untrimmed wheel well lip. A 275/45-18 is the same width and only .3" shorter, BUT when it is mounted on a 18x9.5 rim with only 5.25" backspace (which is zero offset) the tire comparison and wheel offset calculator say the sidewall will be .98" further outboard than my current setup. Clearly, that tire/rim combo would NOT work with my untrimmed wheel well opening because I only have .6" clearance. Maybe that combo will work with your trimmed wheel well opening but I am certain a 18x9.5 with greater backspace (positive offset) would be a better/safer fit. There is lots of room inboard for wider tires and rims on the rear of our first gen Montes, but very little extra room outboard. That means to get fat tires on wider rims to fit safely we need to move the combo inboard by using rims with positive offset - the wider the combo, the more offset is required. Every 6mm of positive offset increase the backspace dimension by 1/4".