Attached two images
.... this tree started from a seed, I believe it is a native maple, but we do have some invasive species

Location Southern New England, USA

Age of Tree - 11 years - 13 years
Height as of Yesterday - 4 feet

Been trimming branches for 5 years for initial shape and to keep it compact

Night Time Tempatures can still get down to the HIGH 20's at night, day time tempatures are stabalizing at about 35 in the morning to a high of 65.

This tree MUST be removed from this spot no later than Fall 2022, it is to close to the water main and we are concerned the roots of this tree will force and break open the water main from the well which could be an expense that we really don't want to take on... The plan all along was to create a bonsai out of the tree.

Images shows overall hight, and the close up shows marked in blue as to where the air layer is planned for the blue box is the total area and the blue arros are the prefered areas for the airlayer cut....

question do I do this NOW mid March or Wait till nightime temps become more stable with out the chance of a freeze

I guess you want to make a layer, the right time for me, know when the leaves are out, the tree will be there in full sap

Why layer though? Why not just use the plant?

In any case, pull out and pot up now, OR layer when the first leaves are out.