With interest rates paying 5% (Google EQ bank GIC Canada), 800k baht currently earns 40k baht in interest (stuck with THB references since Cdn$ amount changes constantly). That more than covers the cost of an agent and doesn't force you to exchange and lock up a considerable chunk of your money in Thailand. An agent can handle everything (including opening your Thai bank account for you) for about 30k baht. Interest rates will either be the same in a year or higher. Exchange rates could be better or worse so that's an unknown.
Commenters constantly say that it's easy to do yourself but besides an agent requiring zero effort, the math clarifies that it's actually cheaper to put your money in a GIC (in Canada) at current rates since it'll earn pretty much nothing in interest sitting in a Thai bank account.
The UK would be expected to provide the best option for healthcare. Sadly, these systems often take longer than they should. Choosing the UK was the decision just about anyone would make. Grief from your loss is expected but you did nothing wrong. It was a sad outcome but life can be cruel some time. Take care during this difficult time.
J&E Concierge. On my appt day I went to their office in the morning and they drove me and 2 others to the license office. Because I already had a US car and motorcycle license, I had a Thai car and motorcycle license by lunch. Appts take a while but for an extra fee, they can expedite an appt.