you were granted 45 days admitted stay/or extension of stay permit until on December 29th, valid until February 13th. You can extend one time for 30 more days for 1900 THB. Maybe the Immigration officer MIGHT grant you the 60-days Covid19-extension valid from the date you visit them, but as a rule you normally first receive the usual 30 days extension, before you can apply for the "unable to fly home covid19-extension". Look out carefully, some information given here was wrong - there are no more border runs possible at the moment !!
and try to get the 60 days unable to travel extension BEFORE 29th of January, because we and nobody knows what will be after this date and if it will be still possible
the lenght of the admitted stay is the difference. The Single Entry Tourist Visa gives you 60 days upon entry and can be extended once, by 30 more days. The STV gives you 90 days on entry, and can be extended two more times by another 90 days
he should do the first money transfer THIS month AND DON'T WAIT. If he waits until January, he might fall short of one month for the "12 months incoming money" proof
it' about correct as Benjamin explained. You need to apply for the 1-year extension of stay based on being married to a Thai husband, no financials needed