Can I Have a Blepharoplasty if There is Still Some Filler Left?

You have found out that fillers are no good for the lower lids. I also recommend fat removal instead of repositioning.  Repositioning of the fat sounds like a good idea, but in reality, it really doesn't do what you think it will and you will return later to simply gave the fat removed.  Keep it simple!

Hyaluronic acid can be dissolved with an injectable enzyme, so it is possible to remove the product before undergoing blepharoplasty. That way, it will be clear to see what microsculpting of fat needs to be done.

It is possible to have eyelid surgery in the presence of lower eyelid filler. However, your first job is really to find the right surgeon. That person should have solid training and reputation. However, you need to study their before and after photos as well.
If there are things in their work you do not like, don't assume because the surgeon is charming or that the are reputed to be "the best," your work will be any better that what you see in the before and after pictures. Remember, the surgeon presents these pictures not as representative of their work but because they represent the absolute best of their work. The right eyelid surgey will assess you and determine the best approach for your particular situation.

I strongly believe that it is best until all of the filler is gone before proceeding with eyelid surgery. Filler present in the tear trough area can masquerade the orbital rim and allow for misjudgment when removing eyelid fat. It can make the surgery more technically difficult and thus increase the chance of a poor outcome.
If you must have the surgery sooner rather than later, hyaluronidase can be applied to the area to dissolve the filler (if a hyaluronic acid was used). The best option, however, is to be patient and wait it out.

You will most likely get various and diverse opinions in answering your question. Personally, I would prefer that your filler be completely gone before performing ablepharoplasty. Any unnatural distortion of the eyelids can potentially effect thedesired contours following surgery. You would only have to wait a matter of monthsbefore all the filler is gone, so why take a chance of creating a problem and potential dissatisfaction?

You can still undergo a blepharoplasty with fat repositioning even though there is some Juvederm filler still in the orbit. It is important to make sure that the Juvederm is not within the orbital septum creating puffiness since this will just extend the healing time significantly. If there is only a minimal amount of filler left in the eyelids, you can go ahead and proceed with the eyelid surgery.

My personal preference is to wait until most of the filler has disappeared, which in the lower eyelids can be more than 6 months after initial injection. This way I can ensure an excellent outcome for the patient.

To be accurate during the surgical procedure you want the filler to be gone. either by time or by dissolving the hyaluronic acid.
It does make the surgery more accurate and precise.

The fillers that are in place should be no reason to not have your lower bleph with fat repositioning. The dissection for the procedure will allow your doc to clear a space along the infraorbital rim to reposition your fat so the filler will not be an issue.

Blepharoplasty can be performed with the filler in place. However, your plastic surgeon can also remove the filler with Hyaluronidase prior to the procedure if they feel it may interfere with their ability to obtain an excellent result.
In general we like to add the filler after the procedure or during in order to place enough fat in the right position. Occasionally there is not enough fat to transpose and filler is required to enhance the result. Best wishes in your recovery.