I don't quite understand. Our vacuum sealer lets you make the bags as long as you want, but it's restricted to 12" wide. We can fit birds up to 5 lbs in those.
When we raised turkeys, we didn't have bags big enough for them. We wrapped them tightly in plastic wrap, with the legs pushed down against the body, (to eliminate as many air-spaces as we could) like store bought ones. then over-wrapped them in freezer paper, taped securely with freezer tape. They stored very well in the freezer, we didn't see any freezer burn. The last one was probably in the freezer about 8 or 9 months before we ate it.
You can buy a heat shrink turkey freezer bag that works better than most any of the bag sealers you can buy for home poultry freezing and long term storage.