cindy i'll answer just for further reference since the OD'ed kitty you are talking about is coming out of the episode now, but i've seen them need IV glucose drip for 3 days straight... but that is for those aunt bertha gave 30 units instead of 3 units type of cases when pet sitting. usually those vet dosed (non-tilly dosed, did no work up to dose) lantus cats like the one on health today will have the episodes of low numbers last under 24 hours.
is lovely that no one here (in LL) has to worry about that kind of stuff, there is so much to be said for working up to a dose in small timed increments based on nadirs. is not fun to try to keep your cat's BG out of the basement for 19+ hours.