60 days on arrival + 30 day extension, border bounce for another 30 then another 30 day extension = 5 months. Assuming you’re not over 50 for a retirement visa and don’t want to go DTV route.
for £920 a month you be fine 👍🏻 If I’m looking after the money including rent, bills, food, motorbike & anything else I needed (within reason) it would only come to £700-750 or so a month 👍🏻