Options...
Clearing the Scheldt would be a very important gain. On the 5th September much of the 15th Army was still in retreat in Flanders. The portion on Walchern/Beveland had not a lot of time to occupy defense positions, set out communications, stock ammunition, or entrench. Having the Candians advance rapidly to cut off the ferry sites & round out the Germans in Flanders would help. You might take a look at dropping a couple brigades of airborne on the ferry sites to disrupt the 15ht Army further. Were the Brit 30th Corp to advance imeadiatly to the neck and cut off that supply route the problems of the 15th Army are compounded.
I've not seen any convincing arguments Pattons 3rd Army could have got across the Rhine, even with all the fuel and airborne in reach. However the city of Trier was within the grasp of 3rd Army. Capturing that complicates German transportation & logistics across a considerable area. Possiblly even to the point of making a major offensive in the Ardennes impractical. If the 3rd Army can secure enough of the this region then the further advance to the Rhine when the ground freezes is quicker & the possiblity of a earlier crossing of the Rhine can be considered.
A third possibility comes from a little known meeting between Devers (6th Army Grp) & Eisenhower in September 1944. Devers argued for the concentration of supplies & reinforcements in his sector, claiming this would allow him to clear his entire area to the Rhine and then cross. He thought this all could be accomplished by sometime in November. Ike said he would think about it & departed. To provide some background here; the 6th AG did not have the supply problems the 12th & 21st AG had. The super port group of Marsailles/Toulon was swiftly restored & fully operational in September. the railroad net in south France was nearly intact, and a high capacity line led straight north from Marsailles into the 6th AG rear, then on to central France. From mid September supplies were being drawn from 6th AG to help alleviate the problems in 12th AG, and material was sent to ComZ as well. In October a entire corps was temporarily detached from 3rd Army to 7th Army to reflect where its supplies came from.
I have gamed out the 'Devers Option' several times. Against a appropriate German reaction Devers prediction is a bit optimistic, but it was consistently possible to cross the Rhine several months early, in Febuary or even January. If the German decisions are less rational & include things like the Ardennes offensive then the upper Rhine is weakened to the point where a bridgehead is possible in December. Reinforcing the upper Rhine to the point of stopping the 6th AG has a high risk of weakening the overall front to where 12th & 21st AG have opportunities open up during the winter.