Change to Thai Elite while in Thailand ?

My Thai Life Companion and me will now definitely retire from Switzerland to LOS until End of coming March, but my Visa is not 100% decided yet, but most likely I will follow the normal non-immigrant-O route since I qualify easily – I would suppose. But just in case a question for the knowing:
Is it possible to change a a) tourist visa or even visa on arrival or c) non-immigrant O to a Thai Elite Visa while in Thailand ? This is meant as a security option if something goes wrong with the standard process to get a retirement extension in case of a) inkl. conversion to non-immi-O. Or c) because of difficulties opening a bank account for the 800K deposit or other strange occurrences.