I have been thinking about your visit to the Inverness area and your wish to see Culloden.The visitor(maybe the new one?)centre might or might not be open,but I had occasion to be in Inverness on Christmas day with not a lot to do,last year.I went to Culloden,it was closed of course and just,ahem, "popped" over the low fence and walked the battlefield.No one was there to bother me and whilst it was slightly surreal, it was a memorable time.Good stout shoes and warm clothing,including a warm hat,is a must.Culloden is only a very few(less than 10) miles from Inverness.

A trip on Loch Ness might happen at the time of year you are thinking about,I cannot say.If it does, be prepared for a cold trip!

All the very best to you both,JS.