Burying a housing you then need to worry about water or snow getting in there
What distance are we talking?
I trenched (2) circuits out from the house, one is maybe 10' away, the 2nd maybe 20' away
Its only another 10-15' to my front fence, didn't feel like digging past my birch tree
Once the new driveway goes in I have a 1/2" conduit already buried to run another circuit (or two) about 50' from the garage
No sidewalks here
I'd put conduit under the sidewalk & have caps on either end
Then uncap when needed & use an extension cord