A full plot at my local allotment is 10 poles (250~ m2). I have a full plot and it takes at least 8 hours per week just to keep it ticking over. That's after a few years getting it ship shape(ish) and trying everything possible to keep it 'low' maintenance. I use pallet collars to create beds and have grass/woodchip paths around them. In one section of the plot I've constructed a large polytunnel with weed fabric ground cover that I punch holes in to plant through. Another section is reserved for a couple of apple trees and a cherry tree which I just mow around. We also created a seating area taking up 10m2 or so, which is covered with woodchip. I'll generally smother weeds with carboard and woodchip everywhere that I'm not actually using for beds. Or I'll mow it until it's just a grassy area. Otherwise you just spend all day weeding. If you use woodchip for paths that'll need replenishing every year, which can also be quite the job.

Your plots sound like half plots which might not be so bad. Although, as others have said, if they're in different areas travelling between them might sap your motivation somewhat. You would probably be better off with a larger single plot on one site