#1 is your arch insulated? Not Bricked but insulated. If not make this a priority keep that heat inside
you shouldnt have no problem finishing it off the arch and filter and bottle right then. Takes two people but can be done. Did it for several years on a 3x10 never had any syrup go bad.
I myself draw off filter and save like others do. Once I have 15/20 gal saved reheat filter a second time into canner check Brix and bottle..