the closest spot is going to be the top rear clearance with the strut.. look in there and get an idea of what clearance you have now. On my 08 I have 18mm between the tire and the strut; this is with 16x6.5et48 and 215/60/16 stock wheels.
so If I had 16x7 et53 the offset would move the wheel center 5mm inboard. But at the same time going from a 6.5 stock wheel to a 7 width would take another 6mm of inside clearance.. (+0.5in = +12mm = +6mm wider on each side) so the wheel would be 11mm closer to the strut.
now the tire, roughly going from 215 to 225 adds 10mm across the width of the tire, so +5mm for each side.
so that combo should end up being 16mm closer to the strut that the stock setup.. and it would have about 2mm clearance. that's pretty close..
I have the RS 6-spokes on my '02 Forester. Currently running a 225/55/16 Blizzak on there and didn't have any rubbing issues until is installed my adjustable lateral links (just have to get the adjustments right and they'll be fine). Plenty of space with both stock suspension and FSTi suspension (1" drop).