I've got a decent amout of experience using single deep setup. Its not all that uncommon in north. Here are just some ramblings---
My biggest take away is that you need bees that are ok in the setup. It can be great for making a crop of honey if you get the bees to cooperate. Honey crops here tend to be a summer event--June/July. Folks that i know using singles are most often specifically targeting comb honey production (basswood, thistle) on commercial scale---generally aimed at middle eastern customers. Bees that tend to do the best seem to carry alot of traits that you might see in a carnica stock---good ability to regulate brood nest based on size of box and environmental factors. If you have bees that dont want to regulate at all they will often tend to make huge clusters and only partially fill the box directly above the excluder/single or they will fill it but then empty that box as soon as the flows slow up. Come fall you will want to see bees that can really turn down the brood production while still making enough winter bees. on the right years with good goldenrod flow they will set themselves up good for winter. but its not so uncommon to find yourself weighing options regarding feeding. weather this spring has been rather cool and wet so it has been more difficult for singles to really take off compared to larger colonies with more resources---so that might make put you in a position for needing to feed then also (but not always) probably the biggest management issue with the setup is come spring when its nearly impossible to keep them in 2 or 3 deeps let alone 1. it takes some pretty intense manipulation at that point. and those bees that typically regulate to flows, weather, space also tend to explode come spring with high swarming tendency so you need a plan regarding that