I have been up to Poplar Lake 3 times, stayed at Old Northwoods Lodge. Everything is great. The dogs run out to meet you, no doors are locked, in fact they don't even have locks, the sauna is open and warm, just take a canoe if you want one. The other side of the spectrum from red tape and frustration. The lake itself is a gem. Take a canoe out for sure.
There are large open areas, there are tons of little islands and bays where you can just glide through on your canoe. I even saw a loon "fly" under my canoe. I also saw a bald eagle try to catch a duck, wow. There is decent fishing, I caught a Northern Pike and a Small Mouth Bass. Also provides access to the BWCA. The BWCA is truly, truly, truly, a gift of a place. Go there and respect it.
You can also go to Grand Marais (eat at Sven & Ole's), go running, hiking, biking, berry picking, cross country skiing, or sightseeing (check out Honeymoon Bluff). There are great things to do all around Poplar Lake and the Grand Marais / Gunflint Trail area.

( I have also stayed at Loon Lake Lodge, Bearksin Lodge, and Gunflint Pines, loved them all, they are on lakes close to Poplar)