What rack do you have right now? I have one of those combo ones that holds 28's and 12's but I don't like it. I like the tubs to go long ways and the 28's just seem like they don't have as much space to thermoregulate. What I'm planning on doing is when my biggest girl gets big enough for a 41 qt I'll get a 41 qt rack (probably one that I can stack one more on top of later and have the racks be at the maximum height I'd want), then when I see my first lock I'll get a v18 rack. Then when hatchlings start to take up more tub space I'll get a 28qt rack for my males and probably double up on the 41qt rack for all my females growing up.
So this way I'll have that combo rack not used and I could use that as a quarantine, although it's a 6 shelf rack so it's not really something small and easy to keep out of the way, but it would work good if I got a lot of snakes at one time (like someone getting out of the hobby selling stuff).
As far as feeding I really wouldn't worry. Most people keep breeder males under 1kg so yours has plenty of body size to sustain him for a long time. I'd just cut back offering him food and only do it every 2 weeks or so, just to avoid any extra stress and wasting rats.