Okay, suggested above was theoretical before a repair was attempted. Detailed below is as to how I proceeded.
When the bottom door gasket was removed, some rot-slots were apparent at the bottom edge of the door. The rot was scraped out, the slots dried with a heat gun, and Minwax Wood Hardener was then applied to the cleaned slots. Wood screws were installed up into the slots for rebar (screw in far enough so that they will be covered by filler). One vertical edge was “formed” with a plastic-wrap covered piece of wood C-clamped to the door panel. Finally, the slots were filled with Minwax Wood Filler. Before you fill, mark the inside of the door where you intend to nail or screw the gasket back on so as not to run into the reinforcing screws when the gasket is reinstalled. Also avoid marking at the old gasket nail holes (fill them with wood filler as well).
To construct the smile wedges, the door opener was disconnected and the bottom of the door placed on a 45” step ladder about 7’ from the door edge. A 2x4 was set from the top of the step ladder on the outside of the door (wedge/door intersection point), to the door edge where it was C-clamped, and level verified. The 2x4 was then C-clamped to the door on the ladder end so there would be no gap between the 2x4 and the door bottom edge. A line was then scribed on the 2x4 at the intersection between it and the smiling edge of the door. An inch or so of the door will be behind the door frame, but ignore this as the elevation change in two inches is negligible.
The smile curvature was gradual enough that the 2x4 wedges could be cut with a circular saw rather than a jig saw.
Since the 2x4 measures 1½” and the door is 1¼” wide, ¼” had to be ripped off the side of the wedge. This was accomplished by creating a table saw out of an 18V Ryobi circular saw and ¼” plywood. A straight piece of wood was screwed onto the plywood 1¼” from the edge of the blade protrusion for the rip fence. The saw switch was secured in the “on” position with a twist-tie; the battery installation/removal turned the saw on/off. The saw sat inverted in a metal milk crate with the plywood table spanning the milk crate opening. Note: the plywood was not cut away the for the saw blade guard. If you do this, be extremely careful of the exposed spinning blade.
Pre-drill the screw holes on the wedge carefully avoiding installing the screws in the old gasket holes or at the marks on the door that indicate where the new gasket screws/nails will be applied. Apply Titebond III generously to the wedge and screw it into the bottom of the door (the 45” step ladder was placed in the middle of the wedge to position the wedge prior to installing the screws). Be sure to put a drop cloth or cardboard on the ground to catch the excess glue. At the narrow end of the wedge, use washers on the screws to prevent the wood from splitting. When the glue has dried, remove the washers, and fill any remaining holes or gaps in the seams between the door and the wedge with wood filler or paintable caulk.
Important: manually raise the garage door slowly until wheels at the bottom of garage door go into the rail curves. The outside bottom edges of the wedges may contact the door jam at this point. If this occurs, lower the door slightly and use a sharp wood chisel to round the wedges from the jams to the outer door edges until the door no longer contacts the jam and rises freely.
After the filler or caulk dries, paint the wedge sides and bottom and replace/reinstall the gasket, screwing or nailing at the marks previously made on the inside of the door. I prefer 1¼” galvanized wood screws and galvanized washers over roofing nails for gasket installation.
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