In the new place, I would set them up side-by-side in the room where they will be let out to exercise, and reserve another area (or multiple areas) of the house for bonding. The exercise space won’t be neutral because it will be close to their home pens. Do not let them out to exercise at the same time in the area near their pens, but alternate who is out in that space. They should only be interacting in a very neutral space while being supervised.

The other alternative (if you have the time and the stamina!) is to try marathon bonding them in the new place from the start. I’ve this before when moving. You basically travel to the new home with the buns together in a carrier (have someone else drive so you can monitor for fighting), and them move them into a large pen together. You want to keep the pen very basic and no litter boxes at first, just pee pads on the floor and a pile of hay. Supervise 24/7 until they are showing lots of positive behaviors (grooming, cuddling, comfort with each other) and no aggression (no nipping, chasing, fighting) for 48 hours. I usually add a litter box after the first overnight if it goes well, and usually I have a good sense after the first overnight as to whether it’s going to work out. Have another pen set up to separate them if needed (like if they keep trying to fight and you are falling asleep).

Given your move to a larger place, here’s a thought: start by setting up separate pens next to each other so they can see and smell each other without direct contact. Continue with the supervised common area time to encourage positive interactions. This way, they can get used to the new space and each other at their own pace. Gradually, you can try more direct bonding sessions in the common area.