That single entry Non O London will issue with no financials just by being over 65 and showing a UK state pension is a saving grace for some people. I don't know of anywhere else that will issue one on that basis.
If the 800,000 isn't available, then a single entry non O from the UK by showing a state pension will give 3 months. Then a SETV from somewhere in the region plus a 30 day extension then a border hop will more or less cover the period he wants from Sept until April.