I might go to Bridge of Orchy and stay here, or I might go to Rannoch Station and stay here. Both come with personal recommendations and both take dogs.

I usually stay in B&Bs rather than hotels because they're usually friendlier, but these don't sound too bad. And someone also suggested doing a walk I've wanted to do for a while, Corrour to Rannoch Station. You get the train to Corrour, just one stop, and walk back. Previously I've stayed at the Corrour station bunkhouse or at the youth hostel at Loch Ossian, and the one time I planned to do the walk to Rannoch Station the snow was so deep I couldn't see the path & decided not to risk it.

Bridge of Orchy is on the West Highland Way, so there is plenty of good walking there too.

If there are no sheep, Bertie can roam off the lead. He ignores any animals bigger than himself, such as cattle and deer. Corrour is a shooting estate, so it's all deer and ponies. Not sure about Bridge of Orchy.