I would feel good about that time frame doing at least two sessions a day. If the hold is up to your expectations and the dog is amped up, the rest is easy.
I know you are finished or close to finishing the hold but I will add some tips that may help others. I train the hold by starting the dog out with a wooden dowel. I don’t like to use a dummie to start with for the simple reason the dog may react and relate the pressure to the dummie. This could cause problems later. I apply pressure until the dog has the dowel in its mouth, then the pressure is released. One of the dogs I am currently training grasped the concept the second day. Now after he is reliably holding the dowel, I will make him take a step to reach for it. Then I will make him move the length of the table. Next I will make him pick it up off the table, first by laying it right in front of him and then making him take a few steps to get the dowel. When I am satisfied, I then will move him off the table and have him grab the dowel from me when I say “hold” or “fetch”. Next I will toss the dowel a few feet in front of him to retrieve. If there is a refusal to pick it up, I will add pressure. If he picks it up but isn’t carrying it properly, I will help him out by letting him make the retrieve and then placing the dowel correctly in his mouth while saying hold. That is important and worth explaining a little better. I like to help the dog out as much as possible. if he is going out and picking the dowel up but not carrying right. I will wait until he returns to me and then get the correct hold. This is coching instead of using pressure. Most of the time the dog will hold it right on the next attempt.
So far all the dog has held is the dowel. I now will take him back to the table and have him hold other objects. Bumpers, caps, thick items, thin items. I want the dog to uderstand that “hold” means any item I tell them to. All I looking for is the dog to “hold” another item. I don’t go through the whole process of making them run up and down the table or pick it up off the ground. Now I switch to bumpers and have the dog do retrieves. I will toss bumpers at different distances and have the dog retrieve. This is where you can amp the dog up and they have fun. make sure their hold remains solid though. Again if the hold is not right, I will correct when they return to me instead of applying pressure.
Now when all is good here, I then return the dog to the table and have them hold a live pigeon. This is going to be differnt for the dog. I use pressure here just as I did with the dowel. When the dog is holding a pigeon, I then switch to a pheasant. Again the dog must dead pheasant the correct way.
Now I have my hold portion finished. I then start doing ladder drills and force to pile. These usually only take a few sessions for the dog to catch on to so it goes pretty quickly.
Hope this helps you out. If the hold is good, you should be able to see great results in 3 or 4 weeks.