Need your help on this rooted cutting, please

Hello everyone, I'm new to to this forum, and I need your advice.
I got a rooted cuttings early December 2006. It came to me leafless but already rooted and in its current pot complete with soil, not bareroot. I left it alone most of the time, watering it whenever the soil is dry to the touch. It's currently living indoor, where it's pretty warm, 65-70 F.
Is it normal for the leaves to take their time, does it need some kind of a dome for humidity to speed up this process?
In the picture you can see the tip on the right is green with what looks like leaves to be, and the left stem is not great looking. Is there something wrong with this cutting? The blackish side is dry to the touch though, so I don't think it's a rot. The whole cutting feels firm as well.
Please let me know what you think of this cutting, is it heading to the right direction? Any advice will be greatly appreciated.
Thank you very much..!!

And one more picture, a close up of the questionable tip.
Thanks again!

First of all it is quite normal for them not to be leafing out yet.
I agree it is unusual for one tip to be showing so much green and the other one to be still dark but as long as it's hard and not squishy I think you are ok. Keep an eye on it though.

The tip on the left in your first picture has died back. You can see the line where it stops. This tip will most likely dry up and fall off in direct sun, and new branches will sprout just below the line from the nodes. You won't see flowers on the new branches this year from that tip, but you may on the other tip. Bottom heat and supplemental light will keep your plumie from declining any further and may even help it to sprout leaves sooner. I don't think that there is a Zone 10 in Northern California. You are probably in Zone 9. There has been record cold in California this year, and many tips of plumerias have become damaged all over. You will probably want to keep yours inside until spring. Welcome to the Plumie Forum!

Wow, you two are fast...! Thank you so much!
I'm going to try the bottom heat, since I have a heat mat just sitting around not doing anything right now.
Clare, thanks for the reminder on the zoning thing. I've been meaning to change it but kept on forgetting. This year's cold snap for sure put me in zone 9b. The chill caused enough casualties on my succulents to make me sad that seeing leaves unfurling on this plumie will sure make me thrilled!
Thanks again for your replies, Dutchlady1 and Clare..!

Sorry about your succulents, Baileykat. I hope they will come back for you in the spring. I had some damage too on my succulents, brugmansias, and other tropicals. We broke a record here when it reached 28 for several hours one night. Good luck with your plumie! That heating pad will definitely make a difference. Add a desk lamp over it for a few hours a night, and you will see a major improvement.

Welcome to the forum...
Could be the light hitting the plant..
The left side could be getting less light then the other side..
I seen this many times..
The best thing IMHO is to never cut back the black tip rot until it is warm out..
The plumies have a natural defense and will seal the wound from inside..
If you cut it back like most peeps then you will be chasing new rot infections as the new cut will invite more problems..

Thank you for your advice, lopaka. Ever since I received this cutting, I haven't done any pruning at all, but something did fall out on its own from that black part, like a small tip that dried and fell off. I'm trying to find a supplemental light for it, hopefully there'll be sign of growth or something on that side afterwards.

Clare, sorry for the damage done on your plants. It went down to 29F here, did a whole lot of damage than I expected. The succulents did me the most though, because they didn't drop dead right away, but waited a week or so and suddenly collapsed, just when I thought they were okay.

Thanks, Baileykat. Same here too -- some of my plants showed damage right away while others took a week or so to start looking grim. Hopefully, we'll both have new growth in a warm spring;-)