I'm not sure why you couldn't get into the Jay site. It seems to be working now.
If you plan to leave for Stowe bright and early to get fresh tracks (should there be any that day), you will probably prefer to stay on the Jay side of the mountain, rather than in Montgomery, because you'll be just off Rte. 100 (from Montgomery you take 118 to 100, and 118 is often not plowed as well and can be terrible in bad weather -- but you should note that staying in either place is about the same distance from Stowe, so if the prices at the places in Montgomery are more appealing, the travel route is not a huge drawback). Another option on the Jay side of the mountain is Inglenook Lodge. Their prices include breakfast, dinner and lift ticket. They have a sauna, indoor pool and hot tub. Snowline's prices include breakfast and discounted lift tickets. They have a pub too. Jay Village Inn has been renovated, has a sauna and hot tub, and their restaurant serves huge portions. Jay Village Inn also has apartments that sleep 6-12 and that might be just perfect for your group.
I wouldn't completely rule out staying at the mountain. They might be running a special during your visit so it's always worth a try to find out the rates on the cheaper condos (plus then you can eat your meals in and save money on food).
If any of you have season passes from other mountains, bring them with you to Jay and you'll get a $38 lift ticket (instead of $58).