I am in Zone 5 (north). I had some trees stored for winter in the nominally heated garage (with a small space heater) but the garage door used to be opened a couple of time a week when needed which allowing cold blast (0F to sometimes as cold as -4F) for short periods of time. After winter now most of the trees are growing fine, a few are really dead but there are some which have live terminal buds and live wood but have not opened the leaf buds this late in June!
I can wait and there is hope that these cold stressed tree with live leaf buds and live wood will eventually leaf out but my question is " Should they be kept in the sun or shade for help in early leafing out?".

I vote full sun. They are not going to think it is time to wake up unless they get warm.

Hi Akram nice to see you posting.

My opinion
long as they are <<< still in dormant state>>>  with all viable buds closed.

If mine they go out on blacktop driveway or cement for warmth and in full sun with possibly a watering depending on how dry mix is.
Only though if there dormant.
Just like doing the fig shuffle .

I have to ask Akram you sure there alive, reason being my garage was in teens this season and below 32 for good spells and trees are fine that were just naked sitting on floor. Was 18 below zero out for the coldest outdoor temps.
But
I had a few young fancy ones cardboard sleeved that died to soil level.
One or 2 young ones did go kaput.

My Kadota did this.  Finally broke buds after heavy thunderstorms followed by 2 85+ days (in the last week or so)

only plant in my yard without leaves...  I kept scratching green under the bark, though.  I was going to cut it in half and root out the cuttings if it hadn't done something by the weekend.

~Chills

Thanks everyone for your response. It will give me ideas.

Martin, my question was about the ones which are surely alive with live trunk, green stems and green buds that have been in a state of 'just about to open' for more than a month now.
There are some that have gradually opened leaf buds and are in full sun for vegetative growth because I do not expect ripe figs from those but their revival is better than re-rooting.
Some died to the soil level. Some among these that dead to the soil level have small shoots coming from the soil and some are really dead obvious from the cracked dried wood and no sign of green anywhere so these kept to a side just in case a miracle happen.

Martin, I am planning an 8'x8'x8' removable enclosure inside one corner of the garage using that silver colour bubble insulation sheets that can be folded away for summer. This will avoid cold blasts and where one 8'x8' side will be attached to the house-wall provide some heat from the heat loss and will use a small heat heater to avoid recurrence of cold stress. I hope this way all the plants will be able to wake up early in the spring.