OK, here goes. I'm an accountant in a seaside resort, so over many years have had numerous clients with small private hotels/B&Bs. I must say, none as big as the OPs, for my clients they were typically 8-15 bedrooms, usually 3/4 story terraces as is typical of seaside towns, some doubled up by being two such properties knocked together.
Average "renovation" costs, even for those bought as going concerns and operational was typically around quarter of a million over an average of 3 to 5 years, that's even for those which appeared to be "cosmetic only". I'd say a large 35 bedroom place could easily burn through a million pounds.
The OP will probably find that the electrics, heating and security/fire systems are all shot. They usually appear functional at surface level, but dig a little, and you usually find "non compliant" aspects where there've been "bodge" jobs in the past, especially if the owners were DIY-ers!
Some of my clients found that previous owners hadn't even painted behind furniture, pictures, headboards, etc. - they'd literally just thrown a bit of paint over the bits that you could visibly see!
A "commercial" quality replacement carpet for hallways, stairs and landings can easily hit £10-£20k for a 3/4/5 story building. You really can't just go to Carpetright and pick at £15 per square metre bog standard carpet as you'd be replacing it again the following year!
If the plan is to make structural changes, i.e. ensuites converted from small box rooms, etc., you end up needing building regs, fire inspections, etc., which always look deeper into other aspects and find areas of non compliance which need to be rectified before they'll sign off the changes.