It seems as though you are on the right track in shopping the . That particular system is designed not only for "stubborn", bull headed dogs, but has the strength in correction levels to accommodate sport and guardian breeds. That system would cover the 5 acres you are looking to contain your dogs in, no problem.
Another system, a bit better manufactured, would be the . It's similar to the PetSafe Stubborn Dog in the strength of corrections, and can cover much more area. This system is the only system that starts you out with 1000' (1 acre's worth) of boundary wire, where all the other systems start you with 500', and you add on from there.
Because you are wanting to temporarily run your wire above the snow, I would definitely opt for the Pro Grade version of these fences (as per the links in this post), because the eXtreme 14 gauge wire is fantastic out in the elements, where the factory packaged 20 gauge wire is thin and more prone to breakage in such environments.
Also, you may want to use the 'customize' section to add some additional landscape staples to your order, which will help secure the wire in place until such time as you are able to bury it.
As for training, the process usually takes about a week (but may take more with some dogs), with 15 minutes invested per day. It's a great time for owner and dog, because of all the positive reinforcement. We have a video on training for one of our wireless systems. The training process is similar, so I'm including that link More information will be included in the documentation included with your fence system.
For the flags, with the white snow we recommend wrapping the flags in a tape of contrasting colors (the darker the better). Since the training isn't a long endeavor, you may be okay with the flag placement. However, if you believe your flags may be buried within that time. you can attach them to lawn sticks or dowel rods to extend them upward.
I hope this information is helpful to you, but please contact us if you have any other questions we can assist with. Thank you kindly for shopping with use.
The best thing to do for stubborn or hard-to-train pets is to buy them a wireless dog fence. The PetSafe Stubborn Dog Extra Collar is one of these wireless dog fences. It is an in-ground fence receiver collar that offers a more intense correction to help train your dog to an In-Ground Pet Fence. It features 4 levels of static correction and a tone with vibration option, so you can find the perfect fit for your dog and start training him to the in-ground system. The PetSafe Stubborn Dog Extra Collar is undoubtedly the best wireless dog fence you’ll ever come across.
PetSafe Stubborn Dog Stay + Play Wireless Fence Receiver Collar
For example, you could purchase the Little Dog In-Ground Fence™ system that comes with a lightweight collar for dogs over 5 pounds and add an extra Stubborn Dog Collar for your St. Bernard mix. The fence covers up to 1/3 acre with the included boundary wire and expands up to 25 acres with extra wire. Or if you have a yard that’s under an acre, go wireless with the Stay+Play Wireless Fence® system and add an extra Stay+Play collar.
The PRF-275-19 is a wireless fence collar. It will not work on the Stubborn Dog in-ground fence.
The collars that are compatible with the Stubborn Dog fence are all the PetSafe collars (except for the YardMax) that are listed on page.
Also, the SportDOG collar on that page will also work on the Stubborn Dog fence. However, it's practically the same collar as the Stubborn Dog collar itself.
Stubborn Dog Stay+Play Wireless Fence® Rechargeable Collar