>>2943616
Rule of thumb is if it's too cold for short sleeves, it's too cold for the bees to come out. Point is they won't be building big population growth. Unless they're over-crowded it's probably safe to leave them in a single box. Less space for them to warm up when it is cold.
>>2943724
>can they be left alone for a week at a time?
Easily. I leave mine for 6 months in the cooler months but we don't have Varroa mite here yet. During swarming season I try to get to them every fortnight to prevent swarming.
I'm going to make a rough guess you could get started for less than $500. If you want a flow hive though I think they're over $1k just for the hive kit, 10x more than regular hardware. Although you theoretically don't have to spend money on extracting equipment (lots of $$$) if you've only got 1 or 2 hives.
I've got between 10 and 15 hives at any one time and need to extract honey in bulk a few times a year. So the equipment is necessary.