You have done your research well. Those are all viable fishing opportunities. Anywhere above the Ashlu bridge on the Squamish River will give you more than 3 days of fishing in of itself.
As of last weekend, your honda civic would be good to go (slowly) up to the 18 km mark and then rutted snow appears which may cause you problems. Don't know if there has been any recent snow.
Spoons and flies are a great combo if you don't want to carry the kitchen sink. If fishing the Squamish, go with heavier spoons such as Koho 45's, R&B wobble spoons or the prime lures in silver, silver/brass, white, chartreuse, minimum 2/5 oz, preferably 2/3 oz. Ff you want to find bulls swing and tap bottom, you might even find some steel. You might find your standard crocs a little light in anything but the slowest water.
For flies, go with minnow patterns at this time of year, although a white/UV chenille bugger in a size 6-8, particularly in coloured water cant be beat. Make sure you have sink tips to swing close to the bottom.
If you have a buddy get him to carry the CP/float set up and short float white or pale pink worms, 4 inches in clear or 6 in slightly coloured water. A pale bead can also still work.
Good luck.