The best investment I ever made for SOTA was buying all the 1:50000 maps for the UK in electronic form. That was £125 in 2007 ISTR. It later entitled me for a free upgrade to the new program and a load of extra features for free. At the end of 2013 I bought the latest upgrade including all the UK at 1:25000HD and 1:50000HD plus streetmapping etc. The licence allows me 5 complete installs so I have it on my desktop, laptop and tablet plus a smaller copy on my works laptop. I always have the whole mapping available without going online. I’ve spent about £450 in total on electronic mapping but it’s money so well spent in my opinion.
Yes, no internet is a killer, you can’t check routes, Google Streetview etc. I’m putting together 3 SOTAxpeditions right now, one for Scotland, 1 for DM/ON and 1 for DM/HB9. Connectivity in the UK is easy as I’ll have 3g/4g plus Wifi in the hotel. It’s more of an issue when in DM/HB9/ON, I can get fixed price internet access on my phone when in Europe but it doesn’t allow tethering. The solution is to print out lots of maps and plans etc.
Still defeat will only make you stronger.