From [url="http://en.wikipedia.org/wiki/Gray_wolf"]Wikipedia[/url]:
Wolves weighing over 54 kg (120 lbs) are uncommon, though exceptionally large individuals have been recorded in Alaska, Canada, and the former Soviet Union. The heaviest recorded gray wolf in North America was killed on 70 Mile River in east-central Alaska on July 12, 1939 and weighed 79.4 kilograms (175 lb), while the heaviest recorded wolf in Eurasia was killed after World War II in Kobeliaky, Poltavskij Region, Ukrainian SSR, and weighed 86 kilograms (190 lb).
165lb would certainly be waaay up there for a wolf in North/Central WI, but is also within the realm of possibility. I'll believe it until it is proven false, rather than the other way around...