First, the GXOR group in (Facebook) FB is like 100x more active than here on IH8MUD. A few of us are active in both forums, but FB gets you 100x more responses.
I live in SoCal, so I cannot answer your questions specifically about your situation up north.
i drove my 2003 GX470 with a mild lift (2.4”), rock sliders, and 33” tires for 5 years and it was great in mountain roads and dirt roads.
I didn’t add front bumper, regear to 4.56, 34s, rear tire swingout, 8.2” rear elocker from a 4R until I decided to do medium rock crawling and overlanding.
Here’s a guide that tries to explain the impact of some mild mods
You just got your GX470 and want to do a mild build to improve looks and off-road capability. You want to stand out over the mall cruisers and soccer moms, but want to keep costs under control. This primer doesn't consider any other repairs or basic maintenance your GX470 needs.
First, lets take a look at the wheels, tires, and rocks sliders to start your ideal mild-build and keep costs down. The brands specified here are just examples of what you can get for those estimated prices as of 4/2018. You can always use your favorite brands and remember that prices continue to change over...
You might want to figure out if there are any local meetups near you or an independent shop that does builds to ask questions specifically to your area.