Well, I know for sure a 6g bucket with a MJ 1200, put the cover on ( just sit it on top as you can't close it because of the power cord ) and will heat your water up to 80 degrees no problem without the use of a heater if left at least overnight. That's what I do for my 58g.
You will need a bigger pump on the larger container, I haven't tried myself but likely a Mag drive or
Ocean Runner pump will do the same. Perhaps not a 35g full of water but probably closer to 20g without the use of a heater.