Generally, the IOs at the border are fairly lenient to Americans that are being sponsored. Generally. Not always, but usually. I know of people that did show up at the border with the U-Haul and their Canadian spouse, showed their PR application proof and were let in. NOT what I would recommend, but it does happen. (Being married for at least a few years seems to be a factor.)
Spouses generally do better when crossing with their Canadian sponsor. When the Canadian makes the request to have the American enter, it seems to hold more weight than an American requesting to stay long term.
So there's no real "correct" answer. If your husband can get a letter from his job saying he's due to return on X date or buy a refundable plane ticket to leave Canada, that would really help. (You obviously return the ticket once you're in Canada - there's usually a small fee to refund it.) That way, if you do take him over the border with you, his story of helping you move carries more weight.
Collect as many opinions as you can and decide what is best for you. Best of luck!