training question about doorbell reactivity

My 18-month-old Borador Newton loses his mind when people come to the door; he pushes me out of the way, jumps, he licks and generally makes a nuisance of himself. What I've been doing is isolating him in the kitchen behind a baby gate, preferably getting him confined before the bell rings if I see a car pull in or someone walking up to the door. I'm generous with dehydrated hot dog and liver treats but he's at the point when the baby gate comes out I have to guide him by the collar and lure him with waving treats under his nose to get him into the kitchen. I've instructed guests to ignore him when he's barking and hopping around behind the gate until he's settled down and quiet at which point I let him come out and greet people (he can be nosy/licking at this point which I'll address later). To me this isn't ideal - I'd much rather have a friendly, courteous dog sitting calmly waiting to be greeted than a nutball behind a gate barking and demanding attention. I'm getting ready to start mat work to reinforce self calming behavior as well as giving him a spot to target away from the door, but what do I do in the meantime? I'm caregiver for my elderly mom who has hospice staff coming in 3-4 times a week and I can't expect them to stand out on the front stoop for 10 minutes while I work on getting him onto his mat and staying there! Should I move his mat into the kitchen and continue confining him until I get a chance to thoroughly proof the behavior in a controlled way or would that create a negative relationship to the mat and just confuse the issue? I've read plenty of tips/methods for training calm greetings at the door but so far I haven't seen this aspect addressed. Obviously I can't just ask everybody to stay away for days/weeks while we're working on this or expect people to stand around outside the door in the cold waiting for Newton to decide to relax! Thanks!