I'd heel it in upright outdoors, otherwise you will have to cut the roots to pot it. If you are going to be gone for 3-4 weeks I hope it doesn't get dry where you live. Might consider mulching it pretty deep after heeling in and watering it. If there is no chance of it breaking dormancy you could heel it in out of sunlight and laying down on its side so the growing hormones won't be flowing up and down.

Thank you for the response! I do have someone to water it for me, and luckily I'll only be gone for 2 of the 4 weeks.

Does your answer change if I have a huge pot? It's about 20 inches across. Just want to increase the chances of survival!